Infinite Interval

From 09a8fef224a3682059fe1adf42957f693a41d242 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@2ndquadrant.com>
Date: Thu, 30 Apr 2020 10:06:49 +0530
Subject: [PATCH] Support infinite interval

This is WIP.

Following things are supported
1. Accepts '+/-infinity' as a valid string input for interval type.
2. Support interval_pl, interval_div
3. Tests in interval.sql for comparison operators working fine.

TODOs
1. Various TODOs in code
2. interval_pl: how to handle infinite values with opposite signs
3. timestamp, timestamptz, date and time arithmetic
4. Fix horology test.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       |   2 +
 src/backend/utils/adt/timestamp.c      | 166 ++++++++++++++++++++++++-
 src/test/regress/expected/interval.out |  80 ++++++++++--
 src/test/regress/sql/interval.sql      |   8 ++
 4 files changed, 242 insertions(+), 14 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index b5b117a8ca..1e98c6dc78 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3634,6 +3634,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f2508c0c4..0c7286b06e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void interval_noend(Interval *interval);
+static bool interval_is_noend(Interval *interval);
+static void interval_nobegin(Interval *interval);
+static bool interval_is_nobegin(Interval *interval);
+static bool interval_not_finite(Interval *interval);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +949,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			interval_noend(result);
+			break;
+
+		case DTK_EARLY:
+			interval_nobegin(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +979,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (interval_not_finite(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1371,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (interval_not_finite(interval))
+		return;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1571,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (interval_is_nobegin(interval))
+		strcpy(str, EARLY);
+	else if (interval_is_noend(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2080,10 +2117,12 @@ timestamp_finite(PG_FUNCTION_ARGS)
 	PG_RETURN_BOOL(!TIMESTAMP_NOT_FINITE(timestamp));
 }
 
+/* TODO: modify this to check finite-ness */
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval *interval = PG_GETARG_INTERVAL_P(0);
+	PG_RETURN_BOOL(!interval_not_finite(interval));
 }
 
 
@@ -2926,8 +2965,27 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
+	/*
+	 * Adding finite interval to an infinite time is going to be infinite in
+	 * the same direction. Adding infinte interval to infinite timestamp in the
+	 * same direction results in an infinite timestamp in the same direction.
+	 * Adding infinite interval to an infinite timestamp with opposite
+	 * direction is not going to yield 0 but some infinity. Since we are adding
+	 * interval to the timestamp the resultant timestamp is an infinity
+	 * preserving the direction.
+	 */
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
+	else if (interval_not_finite(span))
+	{
+		if (interval_is_nobegin(span))
+			TIMESTAMP_NOBEGIN(result);
+		else
+		{
+			Assert(interval_is_noend(span));
+			TIMESTAMP_NOEND(result);
+		}
+	}
 	else
 	{
 		if (span->month != 0)
@@ -3032,8 +3090,27 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
+	/*
+	 * Adding finite interval to an infinite time is going to be infinite in
+	 * the same direction. Adding infinte interval to infinite timestamp in the
+	 * same direction results in an infinite timestamp in the same direction.
+	 * Adding infinite interval to an infinite timestamp with opposite
+	 * direction is not going to yield 0 but some infinity. Since we are adding
+	 * interval to the timestamp the resultant timestamp is an infinity
+	 * preserving the direction.
+	 */
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
+	else if (interval_not_finite(span))
+	{
+		if (interval_is_nobegin(span))
+			TIMESTAMP_NOBEGIN(result);
+		else
+		{
+			Assert(interval_is_noend(span));
+			TIMESTAMP_NOEND(result);
+		}
+	}
 	else
 	{
 		if (span->month != 0)
@@ -3192,6 +3269,21 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * TODO: What if both span1 and span2 are infinite and in oppposite
+	 * direction?
+	 */
+	if (interval_not_finite(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (interval_not_finite(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month + span2->month;
 	/* overflow check copied from int4pl */
 	if (SAMESIGN(span1->month, span2->month) &&
@@ -3362,6 +3454,14 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/* Dividing infinite interval by finite number keeps it infinite. */
+	/* TODO: Do we change the sign of infinity if factor is negative? */
+	if (interval_not_finite(span))
+	{
+		memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -5955,3 +6055,63 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Set the given interval to indicate infinite interval in the future. */
+static void
+interval_noend(Interval *interval)
+{
+	interval->time = DT_NOEND; 
+	interval->day = PG_INT32_MAX;
+	interval->month = PG_INT32_MAX;
+}
+
+/* Does the given interval indicate infinite interval in the future? */
+static bool
+interval_is_noend(Interval *interval)
+{
+	/*
+	 * TODO: Possibly it makes sense to just check one of the fields to reduce
+	 * the number of instructions here. But it's safer to check all the three
+	 * fields.
+	 */
+	return interval->time == DT_NOEND &&
+		   interval->day == PG_INT32_MAX &&
+		   interval->month == PG_INT32_MAX;
+}
+
+/* Set the given interval to indicate infinite interval in the past. */
+static void
+interval_nobegin(Interval *interval)
+{
+	interval->time = DT_NOBEGIN;
+	interval->day = PG_INT32_MIN;
+	interval->month = PG_INT32_MIN;
+}
+
+/* Does the given interval indicate infinite interval in the past? */
+static bool
+interval_is_nobegin(Interval *interval)
+{
+	/*
+	 * TODO: Possibly it makes sense to just check one of the fields to reduce
+	 * the number of instructions here. But it's safer to check all the three
+	 * fields.
+	 */
+	return interval->time == DT_NOBEGIN &&
+		   interval->day == PG_INT32_MIN &&
+		   interval->month == PG_INT32_MIN;
+}
+
+/* Is the given interval infinite? */
+/* TODO: probably a material for a macro. */
+static bool
+interval_not_finite(Interval *interval)
+{
+	return interval_is_nobegin(interval) || interval_is_noend(interval);
+}
+
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..8242d28945 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,19 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +76,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +87,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +136,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +153,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +164,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +174,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +193,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +209,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +218,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +254,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +263,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +273,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +434,20 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 select avg(f1) from interval_tbl;
+   avg    
+----------
+ infinity
+(1 row)
+
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +876,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +888,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..92f60ad005 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,10 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +31,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -141,6 +148,7 @@ SELECT * FROM INTERVAL_TBL;
 -- updating pg_aggregate.agginitval
 
 select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
-- 
2.25.1

From 4c1be4e2aa7abd56967fdce14b100715f3a63fee Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

Following things are supported
1. Accepts '+/-infinity' as a valid string input for interval type.
2. Support interval_pl, interval_div
3. Tests in interval.sql for comparison operators working fine.

TODOs
1. Various TODOs in code
2. interval_pl: how to handle infinite values with opposite signs
3. timestamp, timestamptz, date and time arithmetic
4. Fix horology test.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       |   2 +
 src/backend/utils/adt/timestamp.c      | 166 +++++++-
 src/test/regress/expected/interval.out | 565 ++++++++++++++++++++++++-
 src/test/regress/sql/interval.sql      | 105 +++++
 4 files changed, 824 insertions(+), 14 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index b5b117a8ca..1e98c6dc78 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3634,6 +3634,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f2508c0c4..0c7286b06e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void interval_noend(Interval *interval);
+static bool interval_is_noend(Interval *interval);
+static void interval_nobegin(Interval *interval);
+static bool interval_is_nobegin(Interval *interval);
+static bool interval_not_finite(Interval *interval);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +949,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			interval_noend(result);
+			break;
+
+		case DTK_EARLY:
+			interval_nobegin(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +979,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (interval_not_finite(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1371,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (interval_not_finite(interval))
+		return;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1571,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (interval_is_nobegin(interval))
+		strcpy(str, EARLY);
+	else if (interval_is_noend(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2080,10 +2117,12 @@ timestamp_finite(PG_FUNCTION_ARGS)
 	PG_RETURN_BOOL(!TIMESTAMP_NOT_FINITE(timestamp));
 }
 
+/* TODO: modify this to check finite-ness */
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval *interval = PG_GETARG_INTERVAL_P(0);
+	PG_RETURN_BOOL(!interval_not_finite(interval));
 }
 
 
@@ -2926,8 +2965,27 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
+	/*
+	 * Adding finite interval to an infinite time is going to be infinite in
+	 * the same direction. Adding infinte interval to infinite timestamp in the
+	 * same direction results in an infinite timestamp in the same direction.
+	 * Adding infinite interval to an infinite timestamp with opposite
+	 * direction is not going to yield 0 but some infinity. Since we are adding
+	 * interval to the timestamp the resultant timestamp is an infinity
+	 * preserving the direction.
+	 */
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
+	else if (interval_not_finite(span))
+	{
+		if (interval_is_nobegin(span))
+			TIMESTAMP_NOBEGIN(result);
+		else
+		{
+			Assert(interval_is_noend(span));
+			TIMESTAMP_NOEND(result);
+		}
+	}
 	else
 	{
 		if (span->month != 0)
@@ -3032,8 +3090,27 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
+	/*
+	 * Adding finite interval to an infinite time is going to be infinite in
+	 * the same direction. Adding infinte interval to infinite timestamp in the
+	 * same direction results in an infinite timestamp in the same direction.
+	 * Adding infinite interval to an infinite timestamp with opposite
+	 * direction is not going to yield 0 but some infinity. Since we are adding
+	 * interval to the timestamp the resultant timestamp is an infinity
+	 * preserving the direction.
+	 */
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
+	else if (interval_not_finite(span))
+	{
+		if (interval_is_nobegin(span))
+			TIMESTAMP_NOBEGIN(result);
+		else
+		{
+			Assert(interval_is_noend(span));
+			TIMESTAMP_NOEND(result);
+		}
+	}
 	else
 	{
 		if (span->month != 0)
@@ -3192,6 +3269,21 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * TODO: What if both span1 and span2 are infinite and in oppposite
+	 * direction?
+	 */
+	if (interval_not_finite(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (interval_not_finite(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month + span2->month;
 	/* overflow check copied from int4pl */
 	if (SAMESIGN(span1->month, span2->month) &&
@@ -3362,6 +3454,14 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/* Dividing infinite interval by finite number keeps it infinite. */
+	/* TODO: Do we change the sign of infinity if factor is negative? */
+	if (interval_not_finite(span))
+	{
+		memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -5955,3 +6055,63 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Set the given interval to indicate infinite interval in the future. */
+static void
+interval_noend(Interval *interval)
+{
+	interval->time = DT_NOEND; 
+	interval->day = PG_INT32_MAX;
+	interval->month = PG_INT32_MAX;
+}
+
+/* Does the given interval indicate infinite interval in the future? */
+static bool
+interval_is_noend(Interval *interval)
+{
+	/*
+	 * TODO: Possibly it makes sense to just check one of the fields to reduce
+	 * the number of instructions here. But it's safer to check all the three
+	 * fields.
+	 */
+	return interval->time == DT_NOEND &&
+		   interval->day == PG_INT32_MAX &&
+		   interval->month == PG_INT32_MAX;
+}
+
+/* Set the given interval to indicate infinite interval in the past. */
+static void
+interval_nobegin(Interval *interval)
+{
+	interval->time = DT_NOBEGIN;
+	interval->day = PG_INT32_MIN;
+	interval->month = PG_INT32_MIN;
+}
+
+/* Does the given interval indicate infinite interval in the past? */
+static bool
+interval_is_nobegin(Interval *interval)
+{
+	/*
+	 * TODO: Possibly it makes sense to just check one of the fields to reduce
+	 * the number of instructions here. But it's safer to check all the three
+	 * fields.
+	 */
+	return interval->time == DT_NOBEGIN &&
+		   interval->day == PG_INT32_MIN &&
+		   interval->month == PG_INT32_MIN;
+}
+
+/* Is the given interval infinite? */
+/* TODO: probably a material for a macro. */
+static bool
+interval_not_finite(Interval *interval)
+{
+	return interval_is_nobegin(interval) || interval_is_noend(interval);
+}
+
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..68d48a0b3e 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,19 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +76,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +87,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +136,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +153,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +164,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +174,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +193,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +209,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +218,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +254,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +263,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +273,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +434,20 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 select avg(f1) from interval_tbl;
+   avg    
+----------
+ infinity
+(1 row)
+
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +876,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +888,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1776,3 +1834,488 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT isfinite(interval 'infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT isfinite(interval '-infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR: TODO
+
+SELECT date '-infinity' + interval 'infinity';
+ERROR: TODO
+
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR: TODO
+
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR: TODO
+
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR: TODO
+
+SELECT interval '-infinity' + interval 'infinity';
+ERROR: TODO
+
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' - interval 'infinity';
+ERROR: TODO
+
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR: TODO
+
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity'
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity'
+ERROR: TODO
+
+SELECT timestamp '-infinity' + interval 'infinity'
+ERROR: TODO
+
+SELECT timestamp '-infinity' + interval '-infinity'
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity'
+ERROR: TODO
+
+SELECT timestamp 'infinity' - interval '-infinity'
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity'
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity'
+ERROR: TODO
+
+SELECT time '11:27:42' + interval 'infinity';
+ERROR: TODO
+
+SELECT time '11:27:42' + interval '-infinity';
+ERROR: TODO
+
+SELECT time '11:27:42' - interval 'infinity';
+ERROR: TODO
+
+SELECT time '11:27:42' - interval '-infinity';
+ERROR: TODO
+
+SELECT interval 'infinity' < interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' < interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <= interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' > interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' > interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' >= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' >= interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <> interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <> interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT -interval 'infinity';
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT -interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * -2;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * 2;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * -2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / 3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / -3;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / 3;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / -3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  TODO
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  TODO
+SELECT date_part('month', interval 'infinity');
+ date_part 
+-----------
+
+(1 row)
+
+SELECT date_part('month', interval '-infinity');
+ date_part 
+-----------
+
+(1 row)
+
+SELECT date_trunc('hour', interval 'infinity');
+ interval 
+----------
+ infinity
+(1 row)
+
+SELECT date_trunc('hour', interval '-infinity');
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT extract(month from interval 'infinity');
+ extract 
+---------
+
+(1 row)
+
+SELECT extract(month from interval '-infinity');
+ extract 
+---------
+
+(1 row)
+
+SELECT justify_days(interval 'infinity');
+ interval 
+----------
+ infinity
+(1 row)
+
+SELECT justify_days(interval '-infinity');
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT justify_hours(interval 'infinity');
+ interval 
+----------
+ infinity
+(1 row)
+
+SELECT justify_hours(interval '-infinity');
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT justify_interval(interval 'infinity');
+ interval 
+----------
+ infinity
+(1 row)
+
+SELECT justify_interval(interval '-infinity');
+ interval 
+-----------
+ -infinity
+(1 row)
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..03d50140a4 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,10 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +31,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -141,6 +148,7 @@ SELECT * FROM INTERVAL_TBL;
 -- updating pg_aggregate.agginitval
 
 select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -578,3 +586,100 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT isfinite(interval 'infinity');
+SELECT isfinite(interval '-infinity');
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity'
+SELECT timestamp 'infinity' + interval '-infinity'
+SELECT timestamp '-infinity' + interval 'infinity'
+SELECT timestamp '-infinity' + interval '-infinity'
+SELECT timestamp 'infinity' - interval 'infinity'
+SELECT timestamp 'infinity' - interval '-infinity'
+SELECT timestamp '-infinity' - interval 'infinity'
+SELECT timestamp '-infinity' - interval '-infinity'
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+
+SELECT interval 'infinity' < interval 'infinity';
+SELECT interval 'infinity' < interval '-infinity';
+SELECT interval '-infinity' < interval 'infinity';
+SELECT interval '-infinity' < interval '-infinity';
+SELECT interval 'infinity' <= interval 'infinity';
+SELECT interval 'infinity' <= interval '-infinity';
+SELECT interval '-infinity' <= interval 'infinity';
+SELECT interval '-infinity' <= interval '-infinity';
+SELECT interval 'infinity' > interval 'infinity';
+SELECT interval 'infinity' > interval '-infinity';
+SELECT interval '-infinity' > interval 'infinity';
+SELECT interval '-infinity' > interval '-infinity';
+SELECT interval 'infinity' >= interval 'infinity';
+SELECT interval 'infinity' >= interval '-infinity';
+SELECT interval '-infinity' >= interval 'infinity';
+SELECT interval '-infinity' >= interval '-infinity';
+SELECT interval 'infinity' = interval 'infinity';
+SELECT interval 'infinity' = interval '-infinity';
+SELECT interval '-infinity' = interval 'infinity';
+SELECT interval '-infinity' = interval '-infinity';
+SELECT interval 'infinity' <> interval 'infinity';
+SELECT interval 'infinity' <> interval '-infinity';
+SELECT interval '-infinity' <> interval 'infinity';
+SELECT interval '-infinity' <> interval '-infinity';
+
+SELECT -interval 'infinity';
+SELECT -interval '-infinity';
+SELECT interval 'infinity' * 2;
+SELECT interval 'infinity' * -2;
+SELECT interval '-infinity' * 2;
+SELECT interval '-infinity' * -2;
+SELECT interval 'infinity' / 3;
+SELECT interval 'infinity' / -3;
+SELECT interval '-infinity' / 3;
+SELECT interval '-infinity' / -3;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_part('month', interval 'infinity');
+SELECT date_part('month', interval '-infinity');
+SELECT date_trunc('hour', interval 'infinity');
+SELECT date_trunc('hour', interval '-infinity');
+SELECT extract(month from interval 'infinity');
+SELECT extract(month from interval '-infinity');
+
+SELECT justify_days(interval 'infinity');
+SELECT justify_days(interval '-infinity');
+SELECT justify_hours(interval 'infinity');
+SELECT justify_hours(interval '-infinity');
+SELECT justify_interval(interval 'infinity');
+SELECT justify_interval(interval '-infinity');
-- 
2.34.1

From e6e764dd8f8423f2aec0fb3782f170c59557adf6 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

Following things are supported
1. Accepts '+/-infinity' as a valid string input for interval type.
2. Support interval_pl, interval_div
3. Tests in interval.sql for comparison operators working fine.

TODOs
1. Various TODOs in code
2. interval_pl: how to handle infinite values with opposite signs
3. timestamp, timestamptz, date and time arithmetic
4. Fix horology test.

Ashutosh Bapat
---
 src/backend/utils/adt/date.c           |  20 +
 src/backend/utils/adt/datetime.c       |   2 +
 src/backend/utils/adt/timestamp.c      | 188 +++++++-
 src/include/datatype/timestamp.h       |  22 +
 src/test/regress/expected/interval.out | 613 ++++++++++++++++++++++++-
 src/test/regress/sql/interval.sql      | 121 +++++
 6 files changed, 949 insertions(+), 17 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 1cf7c7652d..a2c9214bcf 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2073,6 +2073,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2091,6 +2096,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2605,6 +2615,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2627,6 +2642,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index b5b117a8ca..1e98c6dc78 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3634,6 +3634,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f2508c0c4..e501e253a6 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void neg_interval_infinite(Interval *interval);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2083,7 +2116,8 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval *interval = PG_GETARG_INTERVAL_P(0);
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2775,6 +2809,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2850,6 +2887,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2888,6 +2928,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2926,10 +2969,29 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with
+	 * different signs results in an error.
+	 */
+	// TODO this logic can probably be combined and cleaned up.
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
+		elog(INFO, "Went to main branch. time: %ld, days: %d, months: %d", span->time, span->day, span->month);
 		if (span->month != 0)
 		{
 			struct pg_tm tt,
@@ -3032,8 +3094,19 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
-		result = timestamp;
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
 	else
 	{
 		if (span->month != 0)
@@ -3133,6 +3206,13 @@ interval_um(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		neg_interval_infinite(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->time = -interval->time;
 	/* overflow check copied from int4um */
 	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
@@ -3192,6 +3272,24 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Adding two infinite intervals with the same signs results
+	 * in an infinite interval with the same sign. Adding two
+	 * infinte intervals with different signs results in an error.
+	 */
+	if ((INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2)) ||
+		(INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2)))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) || INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+
 	result->month = span1->month + span2->month;
 	/* overflow check copied from int4pl */
 	if (SAMESIGN(span1->month, span2->month) &&
@@ -3226,6 +3324,25 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Subtracting two infinite intervals with different signs results
+	 * in an infinite interval with the same sign as the left operand.
+	 * Subtracting two infinte intervals with the same sign results in
+	 * an error.
+	 */
+	if ((INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2)) ||
+		(INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2)))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) || INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+
 	result->month = span1->month - span2->month;
 	/* overflow check copied from int4mi */
 	if (!SAMESIGN(span1->month, span2->month) &&
@@ -3271,6 +3388,18 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but may change
+	 * the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		memcpy(result, span, sizeof(Interval));
+		if (factor < 0.0)
+			neg_interval_infinite(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3362,6 +3491,18 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may change
+	 * the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		memcpy(result, span, sizeof(Interval));
+		if (factor < 0.0)
+			neg_interval_infinite(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3916,6 +4057,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4371,6 +4517,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5253,6 +5405,11 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		// TODO: copy logic from timestamp_part_common
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5955,3 +6112,22 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Negates the given interval if it's infinite */
+static void
+neg_interval_infinite(Interval *interval)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+	{
+		INTERVAL_NOEND(interval);
+	}
+	else if (INTERVAL_IS_NOEND(interval))
+	{
+		INTERVAL_NOBEGIN(interval);
+	}
+}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index d155f1b03b..4c281c9112 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,28 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+// TODO: Should we make custom NOBEGIN and NOEND constants for Interval?
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = DT_NOBEGIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == DT_NOBEGIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = DT_NOEND;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == DT_NOEND && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..2a3e9eaf52 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,19 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +76,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +87,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +136,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +153,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +164,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +174,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +193,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +209,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +218,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +254,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +263,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +273,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +434,20 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 select avg(f1) from interval_tbl;
+   avg    
+----------
+ infinity
+(1 row)
+
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +876,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +888,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1776,3 +1834,536 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT isfinite(interval 'infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT isfinite(interval '-infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity'
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity'
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval 'infinity'
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval '-infinity'
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity'
+ERROR:  TODO
+SELECT timestamp 'infinity' - interval '-infinity'
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity'
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity'
+ERROR:  TODO
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity'
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity'
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval 'infinity'
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval '-infinity'
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity'
+ERROR:  TODO
+SELECT timestamptz 'infinity' - interval '-infinity'
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity'
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity'
+ERROR:  TODO
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  TODO
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  TODO
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  TODO
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' < interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' < interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <= interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' > interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' > interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' >= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' >= interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <> interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <> interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT -interval 'infinity';
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT -interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * -2;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * 2;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * -2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / 3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / -3;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / 3;
+ interval 
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / -3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  TODO
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  TODO
+SELECT date_part('month', interval 'infinity');
+ date_part 
+-----------
+
+(1 row)
+
+SELECT date_part('month', interval '-infinity');
+ date_part 
+-----------
+
+(1 row)
+
+SELECT date_trunc('hour', interval 'infinity');
+ date_trunc 
+------------
+ infinity
+(1 row)
+
+SELECT date_trunc('hour', interval '-infinity');
+ date_trunc 
+------------
+ -infinity
+(1 row)
+
+SELECT extract(month from interval 'infinity');
+ extract 
+---------
+
+(1 row)
+
+SELECT extract(month from interval '-infinity');
+ extract 
+---------
+
+(1 row)
+
+SELECT justify_days(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_days(interval '-infinity');
+ justify_interval 
+------------------
+ -infinity
+(1 row)
+
+SELECT justify_hours(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_hours(interval '-infinity');
+ justify_interval 
+------------------
+ -infinity
+(1 row)
+
+SELECT justify_interval(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_interval(interval '-infinity');
+ justify_interval 
+------------------
+  -infinity
+(1 row)
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..85b8007454 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,10 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +31,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -141,6 +148,7 @@ SELECT * FROM INTERVAL_TBL;
 -- updating pg_aggregate.agginitval
 
 select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -578,3 +586,116 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT isfinite(interval 'infinity');
+SELECT isfinite(interval '-infinity');
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity'
+SELECT timestamp 'infinity' + interval '-infinity'
+SELECT timestamp '-infinity' + interval 'infinity'
+SELECT timestamp '-infinity' + interval '-infinity'
+SELECT timestamp 'infinity' - interval 'infinity'
+SELECT timestamp 'infinity' - interval '-infinity'
+SELECT timestamp '-infinity' - interval 'infinity'
+SELECT timestamp '-infinity' - interval '-infinity'
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity'
+SELECT timestamptz 'infinity' + interval '-infinity'
+SELECT timestamptz '-infinity' + interval 'infinity'
+SELECT timestamptz '-infinity' + interval '-infinity'
+SELECT timestamptz 'infinity' - interval 'infinity'
+SELECT timestamptz 'infinity' - interval '-infinity'
+SELECT timestamptz '-infinity' - interval 'infinity'
+SELECT timestamptz '-infinity' - interval '-infinity'
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT interval 'infinity' < interval 'infinity';
+SELECT interval 'infinity' < interval '-infinity';
+SELECT interval '-infinity' < interval 'infinity';
+SELECT interval '-infinity' < interval '-infinity';
+SELECT interval 'infinity' <= interval 'infinity';
+SELECT interval 'infinity' <= interval '-infinity';
+SELECT interval '-infinity' <= interval 'infinity';
+SELECT interval '-infinity' <= interval '-infinity';
+SELECT interval 'infinity' > interval 'infinity';
+SELECT interval 'infinity' > interval '-infinity';
+SELECT interval '-infinity' > interval 'infinity';
+SELECT interval '-infinity' > interval '-infinity';
+SELECT interval 'infinity' >= interval 'infinity';
+SELECT interval 'infinity' >= interval '-infinity';
+SELECT interval '-infinity' >= interval 'infinity';
+SELECT interval '-infinity' >= interval '-infinity';
+SELECT interval 'infinity' = interval 'infinity';
+SELECT interval 'infinity' = interval '-infinity';
+SELECT interval '-infinity' = interval 'infinity';
+SELECT interval '-infinity' = interval '-infinity';
+SELECT interval 'infinity' <> interval 'infinity';
+SELECT interval 'infinity' <> interval '-infinity';
+SELECT interval '-infinity' <> interval 'infinity';
+SELECT interval '-infinity' <> interval '-infinity';
+
+SELECT -interval 'infinity';
+SELECT -interval '-infinity';
+SELECT interval 'infinity' * 2;
+SELECT interval 'infinity' * -2;
+SELECT interval '-infinity' * 2;
+SELECT interval '-infinity' * -2;
+SELECT interval 'infinity' / 3;
+SELECT interval 'infinity' / -3;
+SELECT interval '-infinity' / 3;
+SELECT interval '-infinity' / -3;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_part('month', interval 'infinity');
+SELECT date_part('month', interval '-infinity');
+SELECT date_trunc('hour', interval 'infinity');
+SELECT date_trunc('hour', interval '-infinity');
+SELECT extract(month from interval 'infinity');
+SELECT extract(month from interval '-infinity');
+
+SELECT justify_days(interval 'infinity');
+SELECT justify_days(interval '-infinity');
+SELECT justify_hours(interval 'infinity');
+SELECT justify_hours(interval '-infinity');
+SELECT justify_interval(interval 'infinity');
+SELECT justify_interval(interval '-infinity');
-- 
2.34.1

From 380cde4061afd6eed4cde938a4c668a2c96bb58f Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

Following things are supported
1. Accepts '+/-infinity' as a valid string input for interval type.
2. Support interval_pl, interval_div
3. Tests in interval.sql for comparison operators working fine.

TODOs
1. Various TODOs in code
2. interval_pl: how to handle infinite values with opposite signs
3. timestamp, timestamptz, date and time arithmetic
4. Fix horology test.

Ashutosh Bapat
---
 src/backend/utils/adt/date.c           |  20 +
 src/backend/utils/adt/datetime.c       |   2 +
 src/backend/utils/adt/timestamp.c      | 330 ++++++++-
 src/include/datatype/timestamp.h       |  22 +
 src/test/regress/expected/interval.out | 953 ++++++++++++++++++++++++-
 src/test/regress/sql/interval.sql      | 182 ++++-
 6 files changed, 1442 insertions(+), 67 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 1cf7c7652d..a2c9214bcf 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2073,6 +2073,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2091,6 +2096,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2605,6 +2615,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2627,6 +2642,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index b5b117a8ca..1e98c6dc78 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3634,6 +3634,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f2508c0c4..d108057ce5 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void negate_interval(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2033,6 +2066,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2050,6 +2085,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2083,7 +2120,8 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval *interval = PG_GETARG_INTERVAL_P(0);
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2775,6 +2813,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2850,6 +2891,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2888,6 +2932,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2926,7 +2973,25 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with
+	 * different signs results in an error.
+	 */
+	// TODO this logic can probably be combined and cleaned up.
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3005,9 +3070,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3032,7 +3095,25 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with
+	 * different signs results in an error.
+	 */
+	// TODO this logic can probably be combined and cleaned up.
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3115,9 +3196,7 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3132,23 +3211,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	negate_interval(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3192,6 +3255,38 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Adding two infinite intervals with the same signs results
+	 * in an infinite interval with the same sign. Adding two
+	 * infinte intervals with different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month + span2->month;
 	/* overflow check copied from int4pl */
 	if (SAMESIGN(span1->month, span2->month) &&
@@ -3226,6 +3321,39 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Subtracting two infinite intervals with different signs results
+	 * in an infinite interval with the same sign as the left operand.
+	 * Subtracting two infinte intervals with the same sign results in
+	 * an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month - span2->month;
 	/* overflow check copied from int4mi */
 	if (!SAMESIGN(span1->month, span2->month) &&
@@ -3271,6 +3399,19 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but may change
+	 * the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3362,6 +3503,19 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may change
+	 * the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3916,6 +4070,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4371,6 +4530,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5230,6 +5395,62 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+// TODO I don't actaully know if this is correct.
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+						 bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+	
+	// TODO: Maybe everything should be returning inf/-inf?
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5253,6 +5474,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteTimestampTzPart(type, val, lowunits,
+												 INTERVAL_IS_NOBEGIN(interval),
+												 false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5955,3 +6204,28 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Negates the given interval */
+static void
+negate_interval(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+	}
+}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index d155f1b03b..4c281c9112 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,28 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+// TODO: Should we make custom NOBEGIN and NOEND constants for Interval?
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = DT_NOBEGIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == DT_NOBEGIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = DT_NOEND;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == DT_NOEND && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..7567d51661 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,19 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +76,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +87,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +136,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +153,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +164,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +174,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +193,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +209,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +218,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +254,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +263,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +273,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +434,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +870,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +882,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1578,31 +1630,31 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1733,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |      |     |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        |      |     |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1821,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1832,832 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+SELECT isfinite(interval 'infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT isfinite(interval '-infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  TODO
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  TODO
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  TODO
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  TODO
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' < interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' < interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <= interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' > interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' > interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' >= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' >= interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <> interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <> interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT -interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT -interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * -2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * 2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * -2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / 3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / -3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / 3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / -3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  TODO
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  TODO
+SELECT date_trunc('hour', interval 'infinity');
+ date_trunc 
+------------
+ infinity
+(1 row)
+
+SELECT date_trunc('hour', interval '-infinity');
+ date_trunc 
+------------
+ -infinity
+(1 row)
+
+SELECT date_part('us', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('us', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('year', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('year', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('decade', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('decade', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('century', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('century', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('millennium', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('millennium', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('epoch', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('epoch', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(us from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(us from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(year from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(year from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(decade from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(decade from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(century from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(century from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(millennium from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(millennium from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(epoch from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(epoch from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT justify_days(interval 'infinity');
+ justify_days 
+--------------
+ infinity
+(1 row)
+
+SELECT justify_days(interval '-infinity');
+ justify_days 
+--------------
+ -infinity
+(1 row)
+
+SELECT justify_hours(interval 'infinity');
+ justify_hours 
+---------------
+ infinity
+(1 row)
+
+SELECT justify_hours(interval '-infinity');
+ justify_hours 
+---------------
+ -infinity
+(1 row)
+
+SELECT justify_interval(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_interval(interval '-infinity');
+ justify_interval 
+------------------
+ -infinity
+(1 row)
+
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..e58135f3cb 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,10 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +31,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -140,7 +147,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -509,13 +516,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +585,168 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+SELECT isfinite(interval 'infinity');
+SELECT isfinite(interval '-infinity');
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT interval 'infinity' < interval 'infinity';
+SELECT interval 'infinity' < interval '-infinity';
+SELECT interval '-infinity' < interval 'infinity';
+SELECT interval '-infinity' < interval '-infinity';
+SELECT interval 'infinity' <= interval 'infinity';
+SELECT interval 'infinity' <= interval '-infinity';
+SELECT interval '-infinity' <= interval 'infinity';
+SELECT interval '-infinity' <= interval '-infinity';
+SELECT interval 'infinity' > interval 'infinity';
+SELECT interval 'infinity' > interval '-infinity';
+SELECT interval '-infinity' > interval 'infinity';
+SELECT interval '-infinity' > interval '-infinity';
+SELECT interval 'infinity' >= interval 'infinity';
+SELECT interval 'infinity' >= interval '-infinity';
+SELECT interval '-infinity' >= interval 'infinity';
+SELECT interval '-infinity' >= interval '-infinity';
+SELECT interval 'infinity' = interval 'infinity';
+SELECT interval 'infinity' = interval '-infinity';
+SELECT interval '-infinity' = interval 'infinity';
+SELECT interval '-infinity' = interval '-infinity';
+SELECT interval 'infinity' <> interval 'infinity';
+SELECT interval 'infinity' <> interval '-infinity';
+SELECT interval '-infinity' <> interval 'infinity';
+SELECT interval '-infinity' <> interval '-infinity';
+
+SELECT -interval 'infinity';
+SELECT -interval '-infinity';
+SELECT interval 'infinity' * 2;
+SELECT interval 'infinity' * -2;
+SELECT interval '-infinity' * 2;
+SELECT interval '-infinity' * -2;
+SELECT interval 'infinity' / 3;
+SELECT interval 'infinity' / -3;
+SELECT interval '-infinity' / 3;
+SELECT interval '-infinity' / -3;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_trunc('hour', interval 'infinity');
+SELECT date_trunc('hour', interval '-infinity');
+
+SELECT date_part('us', interval 'infinity');
+SELECT date_part('us', interval '-infinity');
+SELECT date_part('ms', interval 'infinity');
+SELECT date_part('ms', interval '-infinity');
+SELECT date_part('second', interval 'infinity');
+SELECT date_part('second', interval '-infinity');
+SELECT date_part('minute', interval 'infinity');
+SELECT date_part('minute', interval '-infinity');
+SELECT date_part('hour', interval 'infinity');
+SELECT date_part('hour', interval '-infinity');
+SELECT date_part('day', interval 'infinity');
+SELECT date_part('day', interval '-infinity');
+SELECT date_part('month', interval 'infinity');
+SELECT date_part('month', interval '-infinity');
+SELECT date_part('quarter', interval 'infinity');
+SELECT date_part('quarter', interval '-infinity');
+SELECT date_part('year', interval 'infinity');
+SELECT date_part('year', interval '-infinity');
+SELECT date_part('decade', interval 'infinity');
+SELECT date_part('decade', interval '-infinity');
+SELECT date_part('century', interval 'infinity');
+SELECT date_part('century', interval '-infinity');
+SELECT date_part('millennium', interval 'infinity');
+SELECT date_part('millennium', interval '-infinity');
+SELECT date_part('epoch', interval 'infinity');
+SELECT date_part('epoch', interval '-infinity');
+SELECT extract(us from interval 'infinity');
+SELECT extract(us from interval '-infinity');
+SELECT extract(ms from interval 'infinity');
+SELECT extract(ms from interval '-infinity');
+SELECT extract(second from interval 'infinity');
+SELECT extract(second from interval '-infinity');
+SELECT extract(minute from interval 'infinity');
+SELECT extract(minute from interval '-infinity');
+SELECT extract(hour from interval 'infinity');
+SELECT extract(hour from interval '-infinity');
+SELECT extract(day from interval 'infinity');
+SELECT extract(day from interval '-infinity');
+SELECT extract(month from interval 'infinity');
+SELECT extract(month from interval '-infinity');
+SELECT extract(quarter from interval 'infinity');
+SELECT extract(quarter from interval '-infinity');
+SELECT extract(year from interval 'infinity');
+SELECT extract(year from interval '-infinity');
+SELECT extract(decade from interval 'infinity');
+SELECT extract(decade from interval '-infinity');
+SELECT extract(century from interval 'infinity');
+SELECT extract(century from interval '-infinity');
+SELECT extract(millennium from interval 'infinity');
+SELECT extract(millennium from interval '-infinity');
+SELECT extract(epoch from interval 'infinity');
+SELECT extract(epoch from interval '-infinity');
+
+SELECT justify_days(interval 'infinity');
+SELECT justify_days(interval '-infinity');
+SELECT justify_hours(interval 'infinity');
+SELECT justify_hours(interval '-infinity');
+SELECT justify_interval(interval 'infinity');
+SELECT justify_interval(interval '-infinity');
-- 
2.34.1

From 518c59be586abf5779c5727c2117b6a46b466503 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

Following things are supported
1. Accepts '+/-infinity' as a valid string input for interval type.
2. Support interval_pl, interval_div
3. Tests in interval.sql for comparison operators working fine.

TODOs
1. Various TODOs in code
2. interval_pl: how to handle infinite values with opposite signs
3. timestamp, timestamptz, date and time arithmetic
4. Fix horology test.

Ashutosh Bapat
---
 src/backend/utils/adt/date.c           |  20 +
 src/backend/utils/adt/datetime.c       |  14 +-
 src/backend/utils/adt/timestamp.c      | 332 ++++++++-
 src/include/datatype/timestamp.h       |  22 +
 src/test/regress/expected/horology.out |   6 +-
 src/test/regress/expected/interval.out | 953 ++++++++++++++++++++++++-
 src/test/regress/sql/horology.sql      |   6 +-
 src/test/regress/sql/interval.sql      | 182 ++++-
 8 files changed, 1460 insertions(+), 75 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 1cf7c7652d..c6259cd9c1 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2073,6 +2073,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2091,6 +2096,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2605,6 +2615,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2627,6 +2642,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index b5b117a8ca..b60d91dfb8 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -70,7 +70,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -977,7 +977,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1927,7 +1927,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -3232,7 +3232,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3634,6 +3634,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4039,7 +4041,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4918,7 +4920,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f2508c0c4..bbdf0cfdea 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void negate_interval(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2033,6 +2066,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2050,6 +2085,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2083,7 +2120,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2775,6 +2814,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2850,6 +2892,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2888,6 +2933,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2926,7 +2974,25 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	/* TODO this logic can probably be combined and cleaned up. */
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3005,9 +3071,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3032,7 +3096,25 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	/* TODO this logic can probably be combined and cleaned up. */
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3115,9 +3197,7 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3132,23 +3212,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	negate_interval(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3192,6 +3256,39 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	/* TODO can be combined and simplified */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month + span2->month;
 	/* overflow check copied from int4pl */
 	if (SAMESIGN(span1->month, span2->month) &&
@@ -3226,6 +3323,39 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	/* TODO can be simplified and cleaned up */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month - span2->month;
 	/* overflow check copied from int4mi */
 	if (!SAMESIGN(span1->month, span2->month) &&
@@ -3271,6 +3401,19 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3362,6 +3505,19 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3916,6 +4072,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4371,6 +4532,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5230,6 +5397,62 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+/*  TODO I don't actaully know if this is correct. */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	/* TODO: Maybe everything should be returning inf/-inf? */
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5253,6 +5476,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteTimestampTzPart(type, val, lowunits,
+												 INTERVAL_IS_NOBEGIN(interval),
+												 false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5955,3 +6206,28 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Negates the given interval */
+static void
+negate_interval(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+	}
+}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index d155f1b03b..ed7b2cc403 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,28 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*  TODO: Should we make custom NOBEGIN and NOEND constants for Interval? */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = DT_NOBEGIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == DT_NOBEGIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = DT_NOEND;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == DT_NOEND && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..a31f17f3fb 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,19 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +76,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +87,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +136,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +153,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +164,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +174,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +193,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +209,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +218,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +254,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +263,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +273,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +434,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +870,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +882,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1578,31 +1630,31 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1733,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |      |     |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        |      |     |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1821,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1832,832 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+SELECT isfinite(interval 'infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT isfinite(interval '-infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT interval 'infinity' < interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' < interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <= interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' > interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' > interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' >= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' >= interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <> interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <> interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT -interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT -interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * -2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * 2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * -2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / 3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / -3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / 3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / -3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_trunc('hour', interval 'infinity');
+ date_trunc 
+------------
+ infinity
+(1 row)
+
+SELECT date_trunc('hour', interval '-infinity');
+ date_trunc 
+------------
+ -infinity
+(1 row)
+
+SELECT date_part('us', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('us', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('year', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('year', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('decade', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('decade', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('century', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('century', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('millennium', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('millennium', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('epoch', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('epoch', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(us from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(us from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(year from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(year from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(decade from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(decade from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(century from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(century from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(millennium from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(millennium from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(epoch from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(epoch from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT justify_days(interval 'infinity');
+ justify_days 
+--------------
+ infinity
+(1 row)
+
+SELECT justify_days(interval '-infinity');
+ justify_days 
+--------------
+ -infinity
+(1 row)
+
+SELECT justify_hours(interval 'infinity');
+ justify_hours 
+---------------
+ infinity
+(1 row)
+
+SELECT justify_hours(interval '-infinity');
+ justify_hours 
+---------------
+ -infinity
+(1 row)
+
+SELECT justify_interval(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_interval(interval '-infinity');
+ justify_interval 
+------------------
+ -infinity
+(1 row)
+
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..e58135f3cb 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,10 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +31,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -140,7 +147,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -509,13 +516,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +585,168 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+SELECT isfinite(interval 'infinity');
+SELECT isfinite(interval '-infinity');
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT interval 'infinity' < interval 'infinity';
+SELECT interval 'infinity' < interval '-infinity';
+SELECT interval '-infinity' < interval 'infinity';
+SELECT interval '-infinity' < interval '-infinity';
+SELECT interval 'infinity' <= interval 'infinity';
+SELECT interval 'infinity' <= interval '-infinity';
+SELECT interval '-infinity' <= interval 'infinity';
+SELECT interval '-infinity' <= interval '-infinity';
+SELECT interval 'infinity' > interval 'infinity';
+SELECT interval 'infinity' > interval '-infinity';
+SELECT interval '-infinity' > interval 'infinity';
+SELECT interval '-infinity' > interval '-infinity';
+SELECT interval 'infinity' >= interval 'infinity';
+SELECT interval 'infinity' >= interval '-infinity';
+SELECT interval '-infinity' >= interval 'infinity';
+SELECT interval '-infinity' >= interval '-infinity';
+SELECT interval 'infinity' = interval 'infinity';
+SELECT interval 'infinity' = interval '-infinity';
+SELECT interval '-infinity' = interval 'infinity';
+SELECT interval '-infinity' = interval '-infinity';
+SELECT interval 'infinity' <> interval 'infinity';
+SELECT interval 'infinity' <> interval '-infinity';
+SELECT interval '-infinity' <> interval 'infinity';
+SELECT interval '-infinity' <> interval '-infinity';
+
+SELECT -interval 'infinity';
+SELECT -interval '-infinity';
+SELECT interval 'infinity' * 2;
+SELECT interval 'infinity' * -2;
+SELECT interval '-infinity' * 2;
+SELECT interval '-infinity' * -2;
+SELECT interval 'infinity' / 3;
+SELECT interval 'infinity' / -3;
+SELECT interval '-infinity' / 3;
+SELECT interval '-infinity' / -3;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_trunc('hour', interval 'infinity');
+SELECT date_trunc('hour', interval '-infinity');
+
+SELECT date_part('us', interval 'infinity');
+SELECT date_part('us', interval '-infinity');
+SELECT date_part('ms', interval 'infinity');
+SELECT date_part('ms', interval '-infinity');
+SELECT date_part('second', interval 'infinity');
+SELECT date_part('second', interval '-infinity');
+SELECT date_part('minute', interval 'infinity');
+SELECT date_part('minute', interval '-infinity');
+SELECT date_part('hour', interval 'infinity');
+SELECT date_part('hour', interval '-infinity');
+SELECT date_part('day', interval 'infinity');
+SELECT date_part('day', interval '-infinity');
+SELECT date_part('month', interval 'infinity');
+SELECT date_part('month', interval '-infinity');
+SELECT date_part('quarter', interval 'infinity');
+SELECT date_part('quarter', interval '-infinity');
+SELECT date_part('year', interval 'infinity');
+SELECT date_part('year', interval '-infinity');
+SELECT date_part('decade', interval 'infinity');
+SELECT date_part('decade', interval '-infinity');
+SELECT date_part('century', interval 'infinity');
+SELECT date_part('century', interval '-infinity');
+SELECT date_part('millennium', interval 'infinity');
+SELECT date_part('millennium', interval '-infinity');
+SELECT date_part('epoch', interval 'infinity');
+SELECT date_part('epoch', interval '-infinity');
+SELECT extract(us from interval 'infinity');
+SELECT extract(us from interval '-infinity');
+SELECT extract(ms from interval 'infinity');
+SELECT extract(ms from interval '-infinity');
+SELECT extract(second from interval 'infinity');
+SELECT extract(second from interval '-infinity');
+SELECT extract(minute from interval 'infinity');
+SELECT extract(minute from interval '-infinity');
+SELECT extract(hour from interval 'infinity');
+SELECT extract(hour from interval '-infinity');
+SELECT extract(day from interval 'infinity');
+SELECT extract(day from interval '-infinity');
+SELECT extract(month from interval 'infinity');
+SELECT extract(month from interval '-infinity');
+SELECT extract(quarter from interval 'infinity');
+SELECT extract(quarter from interval '-infinity');
+SELECT extract(year from interval 'infinity');
+SELECT extract(year from interval '-infinity');
+SELECT extract(decade from interval 'infinity');
+SELECT extract(decade from interval '-infinity');
+SELECT extract(century from interval 'infinity');
+SELECT extract(century from interval '-infinity');
+SELECT extract(millennium from interval 'infinity');
+SELECT extract(millennium from interval '-infinity');
+SELECT extract(epoch from interval 'infinity');
+SELECT extract(epoch from interval '-infinity');
+
+SELECT justify_days(interval 'infinity');
+SELECT justify_days(interval '-infinity');
+SELECT justify_hours(interval 'infinity');
+SELECT justify_hours(interval '-infinity');
+SELECT justify_interval(interval 'infinity');
+SELECT justify_interval(interval '-infinity');
-- 
2.34.1

From 2110bbe8be4b1c5c66eb48c35b958d84352a6287 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

Following things are supported
1. Accepts '+/-infinity' as a valid string input for interval type.
2. Support interval_pl, interval_div
3. Tests in interval.sql for comparison operators working fine.

TODOs
1. Various TODOs in code
2. interval_pl: how to handle infinite values with opposite signs
3. timestamp, timestamptz, date and time arithmetic
4. Fix horology test.

Ashutosh Bapat
---
 src/backend/utils/adt/date.c           |  20 +
 src/backend/utils/adt/datetime.c       |  14 +-
 src/backend/utils/adt/timestamp.c      | 347 ++++++++-
 src/include/datatype/timestamp.h       |  22 +
 src/test/regress/expected/horology.out |   6 +-
 src/test/regress/expected/interval.out | 993 ++++++++++++++++++++++++-
 src/test/regress/sql/horology.sql      |   6 +-
 src/test/regress/sql/interval.sql      | 194 ++++-
 8 files changed, 1527 insertions(+), 75 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 1cf7c7652d..c6259cd9c1 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2073,6 +2073,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2091,6 +2096,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2605,6 +2615,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2627,6 +2642,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index b5b117a8ca..b60d91dfb8 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -70,7 +70,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -977,7 +977,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1927,7 +1927,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -3232,7 +3232,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3634,6 +3634,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4039,7 +4041,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4918,7 +4920,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f2508c0c4..e672ee3728 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void negate_interval(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2033,6 +2066,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2050,6 +2085,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2083,7 +2120,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2775,6 +2814,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2850,6 +2892,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2888,6 +2933,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2926,7 +2974,25 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	/* TODO this logic can probably be combined and cleaned up. */
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3005,9 +3071,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3032,7 +3096,25 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	/* TODO this logic can probably be combined and cleaned up. */
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3115,9 +3197,7 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3132,23 +3212,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	negate_interval(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3192,6 +3256,39 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	/* TODO can be combined and simplified */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month + span2->month;
 	/* overflow check copied from int4pl */
 	if (SAMESIGN(span1->month, span2->month) &&
@@ -3226,6 +3323,39 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	/* TODO can be simplified and cleaned up */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("TODO")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month - span2->month;
 	/* overflow check copied from int4mi */
 	if (!SAMESIGN(span1->month, span2->month) &&
@@ -3271,6 +3401,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3362,6 +3510,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3916,6 +4087,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4371,6 +4547,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5230,6 +5412,62 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+/*  TODO I don't actaully know if this is correct. */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	/* TODO: Maybe everything should be returning inf/-inf? */
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5253,6 +5491,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteTimestampTzPart(type, val, lowunits,
+												 INTERVAL_IS_NOBEGIN(interval),
+												 false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5955,3 +6221,28 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Negates the given interval */
+static void
+negate_interval(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+	}
+}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index d155f1b03b..ed7b2cc403 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,28 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*  TODO: Should we make custom NOBEGIN and NOEND constants for Interval? */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = DT_NOBEGIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == DT_NOBEGIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = DT_NOEND;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == DT_NOEND && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..bd503d7895 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,19 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +76,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +87,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +136,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +153,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +164,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +174,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +193,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +209,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +218,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +254,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +263,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +273,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +434,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +870,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +882,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1578,31 +1630,31 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1733,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |      |     |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        |      |     |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1821,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1832,872 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+SELECT isfinite(interval 'infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT isfinite(interval '-infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  TODO
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  TODO
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  TODO
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT interval 'infinity' < interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' < interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <= interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' > interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' > interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' >= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' >= interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <> interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <> interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT -interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT -interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * -2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * 2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * -2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / -3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / 3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / -3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_trunc('hour', interval 'infinity');
+ date_trunc 
+------------
+ infinity
+(1 row)
+
+SELECT date_trunc('hour', interval '-infinity');
+ date_trunc 
+------------
+ -infinity
+(1 row)
+
+SELECT date_part('us', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('us', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('year', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('year', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('decade', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('decade', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('century', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('century', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('millennium', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('millennium', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('epoch', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('epoch', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(us from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(us from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(year from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(year from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(decade from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(decade from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(century from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(century from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(millennium from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(millennium from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(epoch from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(epoch from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT justify_days(interval 'infinity');
+ justify_days 
+--------------
+ infinity
+(1 row)
+
+SELECT justify_days(interval '-infinity');
+ justify_days 
+--------------
+ -infinity
+(1 row)
+
+SELECT justify_hours(interval 'infinity');
+ justify_hours 
+---------------
+ infinity
+(1 row)
+
+SELECT justify_hours(interval '-infinity');
+ justify_hours 
+---------------
+ -infinity
+(1 row)
+
+SELECT justify_interval(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_interval(interval '-infinity');
+ justify_interval 
+------------------
+ -infinity
+(1 row)
+
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..901da3cc1e 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,10 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
+
+--TODO: Add tests for operators etc. by looking at the other tests below
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +31,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -140,7 +147,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -509,13 +516,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +585,180 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+SELECT isfinite(interval 'infinity');
+SELECT isfinite(interval '-infinity');
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT interval 'infinity' < interval 'infinity';
+SELECT interval 'infinity' < interval '-infinity';
+SELECT interval '-infinity' < interval 'infinity';
+SELECT interval '-infinity' < interval '-infinity';
+SELECT interval 'infinity' <= interval 'infinity';
+SELECT interval 'infinity' <= interval '-infinity';
+SELECT interval '-infinity' <= interval 'infinity';
+SELECT interval '-infinity' <= interval '-infinity';
+SELECT interval 'infinity' > interval 'infinity';
+SELECT interval 'infinity' > interval '-infinity';
+SELECT interval '-infinity' > interval 'infinity';
+SELECT interval '-infinity' > interval '-infinity';
+SELECT interval 'infinity' >= interval 'infinity';
+SELECT interval 'infinity' >= interval '-infinity';
+SELECT interval '-infinity' >= interval 'infinity';
+SELECT interval '-infinity' >= interval '-infinity';
+SELECT interval 'infinity' = interval 'infinity';
+SELECT interval 'infinity' = interval '-infinity';
+SELECT interval '-infinity' = interval 'infinity';
+SELECT interval '-infinity' = interval '-infinity';
+SELECT interval 'infinity' <> interval 'infinity';
+SELECT interval 'infinity' <> interval '-infinity';
+SELECT interval '-infinity' <> interval 'infinity';
+SELECT interval '-infinity' <> interval '-infinity';
+
+SELECT -interval 'infinity';
+SELECT -interval '-infinity';
+SELECT interval 'infinity' * 2;
+SELECT interval 'infinity' * -2;
+SELECT interval '-infinity' * 2;
+SELECT interval '-infinity' * -2;
+SELECT interval 'infinity' * 'infinity';
+SELECT interval 'infinity' * '-infinity';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'infinity';
+SELECT interval '-infinity' * '-infinity';
+SELECT interval '-infinity' * 'nan';
+SELECT interval 'infinity' / 3;
+SELECT interval 'infinity' / -3;
+SELECT interval '-infinity' / 3;
+SELECT interval '-infinity' / -3;
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_trunc('hour', interval 'infinity');
+SELECT date_trunc('hour', interval '-infinity');
+
+SELECT date_part('us', interval 'infinity');
+SELECT date_part('us', interval '-infinity');
+SELECT date_part('ms', interval 'infinity');
+SELECT date_part('ms', interval '-infinity');
+SELECT date_part('second', interval 'infinity');
+SELECT date_part('second', interval '-infinity');
+SELECT date_part('minute', interval 'infinity');
+SELECT date_part('minute', interval '-infinity');
+SELECT date_part('hour', interval 'infinity');
+SELECT date_part('hour', interval '-infinity');
+SELECT date_part('day', interval 'infinity');
+SELECT date_part('day', interval '-infinity');
+SELECT date_part('month', interval 'infinity');
+SELECT date_part('month', interval '-infinity');
+SELECT date_part('quarter', interval 'infinity');
+SELECT date_part('quarter', interval '-infinity');
+SELECT date_part('year', interval 'infinity');
+SELECT date_part('year', interval '-infinity');
+SELECT date_part('decade', interval 'infinity');
+SELECT date_part('decade', interval '-infinity');
+SELECT date_part('century', interval 'infinity');
+SELECT date_part('century', interval '-infinity');
+SELECT date_part('millennium', interval 'infinity');
+SELECT date_part('millennium', interval '-infinity');
+SELECT date_part('epoch', interval 'infinity');
+SELECT date_part('epoch', interval '-infinity');
+SELECT extract(us from interval 'infinity');
+SELECT extract(us from interval '-infinity');
+SELECT extract(ms from interval 'infinity');
+SELECT extract(ms from interval '-infinity');
+SELECT extract(second from interval 'infinity');
+SELECT extract(second from interval '-infinity');
+SELECT extract(minute from interval 'infinity');
+SELECT extract(minute from interval '-infinity');
+SELECT extract(hour from interval 'infinity');
+SELECT extract(hour from interval '-infinity');
+SELECT extract(day from interval 'infinity');
+SELECT extract(day from interval '-infinity');
+SELECT extract(month from interval 'infinity');
+SELECT extract(month from interval '-infinity');
+SELECT extract(quarter from interval 'infinity');
+SELECT extract(quarter from interval '-infinity');
+SELECT extract(year from interval 'infinity');
+SELECT extract(year from interval '-infinity');
+SELECT extract(decade from interval 'infinity');
+SELECT extract(decade from interval '-infinity');
+SELECT extract(century from interval 'infinity');
+SELECT extract(century from interval '-infinity');
+SELECT extract(millennium from interval 'infinity');
+SELECT extract(millennium from interval '-infinity');
+SELECT extract(epoch from interval 'infinity');
+SELECT extract(epoch from interval '-infinity');
+
+SELECT justify_days(interval 'infinity');
+SELECT justify_days(interval '-infinity');
+SELECT justify_hours(interval 'infinity');
+SELECT justify_hours(interval '-infinity');
+SELECT justify_interval(interval 'infinity');
+SELECT justify_interval(interval '-infinity');
-- 
2.34.1

From 65aceb25bc090375b60d140b1630cabcc90f1c9c Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

TODOs
1. Various TODOs in code.
2. Correctly implement interval_part for infinite intervals.
3. Test consolidation.
4. Should we just use the months field to test for infinity?

Ashutosh Bapat and Joe Koshakow
---
 src/backend/utils/adt/date.c           |   20 +
 src/backend/utils/adt/datetime.c       |   14 +-
 src/backend/utils/adt/timestamp.c      |  372 ++++++++-
 src/include/datatype/timestamp.h       |   22 +
 src/test/regress/expected/horology.out |    6 +-
 src/test/regress/expected/interval.out | 1006 +++++++++++++++++++++++-
 src/test/regress/sql/horology.sql      |    6 +-
 src/test/regress/sql/interval.sql      |  200 ++++-
 8 files changed, 1571 insertions(+), 75 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 1cf7c7652d..c6259cd9c1 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2073,6 +2073,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2091,6 +2096,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2605,6 +2615,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2627,6 +2642,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index b5b117a8ca..b60d91dfb8 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -70,7 +70,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -977,7 +977,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1927,7 +1927,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -3232,7 +3232,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3634,6 +3634,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4039,7 +4041,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4918,7 +4920,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f2508c0c4..013dc40de2 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void negate_interval(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2033,6 +2066,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2050,6 +2085,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2083,7 +2120,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2775,6 +2814,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2850,6 +2892,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2888,6 +2933,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2926,7 +2974,25 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	/* TODO this logic can probably be combined and cleaned up. */
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite values with opposite signs")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3005,9 +3071,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3032,7 +3096,25 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	/* TODO this logic can probably be combined and cleaned up. */
+	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+		TIMESTAMP_NOEND(result);
+	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite values with opposite signs")));
+	else if (INTERVAL_IS_NOBEGIN(span))
+		TIMESTAMP_NOBEGIN(result);
+	else if (INTERVAL_IS_NOEND(span))
+		TIMESTAMP_NOEND(result);
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3115,9 +3197,7 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3132,23 +3212,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	negate_interval(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3192,6 +3256,39 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	/* TODO can be combined and simplified */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite values with opposite signs")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month + span2->month;
 	/* overflow check copied from int4pl */
 	if (SAMESIGN(span1->month, span2->month) &&
@@ -3214,6 +3311,11 @@ interval_pl(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3226,6 +3328,39 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	/* TODO can be simplified and cleaned up */
+	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2))
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2))
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite values with the same signs")));
+	}
+	else if (INTERVAL_NOT_FINITE(span1))
+	{
+		memcpy(result, span1, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+	{
+		memcpy(result, span2, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = span1->month - span2->month;
 	/* overflow check copied from int4mi */
 	if (!SAMESIGN(span1->month, span2->month) &&
@@ -3248,6 +3383,11 @@ interval_mi(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3271,6 +3411,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3331,6 +3489,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3362,6 +3525,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3383,6 +3569,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3916,6 +4107,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4371,6 +4567,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5230,6 +5432,62 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+/*  TODO I don't actaully know if this is correct. */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	/* TODO: Maybe everything should be returning inf/-inf? */
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5253,6 +5511,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteTimestampTzPart(type, val, lowunits,
+												 INTERVAL_IS_NOBEGIN(interval),
+												 false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5955,3 +6241,33 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Negates the given interval */
+static void
+negate_interval(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index d155f1b03b..ed7b2cc403 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,28 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*  TODO: Should we make custom NOBEGIN and NOEND constants for Interval? */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = DT_NOBEGIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == DT_NOBEGIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = DT_NOEND;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == DT_NOEND && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..c76df77093 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +86,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +135,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +152,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +163,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +173,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +192,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +208,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +217,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +253,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +262,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +272,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +433,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +869,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +881,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1578,31 +1629,31 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1732,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |      |     |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        |      |     |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1820,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1831,886 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+SELECT isfinite(interval 'infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT isfinite(interval '-infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  cannot subtract infinite values with the same signs
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  cannot subtract infinite values with the same signs
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT interval 'infinity' < interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' < interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' < interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <= interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' <= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' > interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' > interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' > interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' >= interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' >= interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' >= interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' = interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval '-infinity' = interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval 'infinity' <> interval 'infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT interval 'infinity' <> interval '-infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval 'infinity';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT interval '-infinity' <> interval '-infinity';
+ ?column? 
+----------
+ f
+(1 row)
+
+SELECT -interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT -interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * -2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * 2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * -2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / -3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / 3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / -3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_trunc('hour', interval 'infinity');
+ date_trunc 
+------------
+ infinity
+(1 row)
+
+SELECT date_trunc('hour', interval '-infinity');
+ date_trunc 
+------------
+ -infinity
+(1 row)
+
+SELECT date_part('us', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('us', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('ms', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('second', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('minute', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('hour', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('day', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('month', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval 'infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('quarter', interval '-infinity');
+ date_part 
+-----------
+          
+(1 row)
+
+SELECT date_part('year', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('year', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('decade', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('decade', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('century', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('century', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('millennium', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('millennium', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT date_part('epoch', interval 'infinity');
+ date_part 
+-----------
+  Infinity
+(1 row)
+
+SELECT date_part('epoch', interval '-infinity');
+ date_part 
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(us from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(us from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(ms from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(second from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(minute from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(hour from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(day from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(month from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval 'infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(quarter from interval '-infinity');
+ extract 
+---------
+        
+(1 row)
+
+SELECT extract(year from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(year from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(decade from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(decade from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(century from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(century from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(millennium from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(millennium from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT extract(epoch from interval 'infinity');
+ extract  
+----------
+ Infinity
+(1 row)
+
+SELECT extract(epoch from interval '-infinity');
+  extract  
+-----------
+ -Infinity
+(1 row)
+
+SELECT justify_days(interval 'infinity');
+ justify_days 
+--------------
+ infinity
+(1 row)
+
+SELECT justify_days(interval '-infinity');
+ justify_days 
+--------------
+ -infinity
+(1 row)
+
+SELECT justify_hours(interval 'infinity');
+ justify_hours 
+---------------
+ infinity
+(1 row)
+
+SELECT justify_hours(interval '-infinity');
+ justify_hours 
+---------------
+ -infinity
+(1 row)
+
+SELECT justify_interval(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_interval(interval '-infinity');
+ justify_interval 
+------------------
+ -infinity
+(1 row)
+
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..82f3180221 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +29,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -140,7 +145,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -509,13 +514,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +583,188 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+SELECT isfinite(interval 'infinity');
+SELECT isfinite(interval '-infinity');
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT interval 'infinity' < interval 'infinity';
+SELECT interval 'infinity' < interval '-infinity';
+SELECT interval '-infinity' < interval 'infinity';
+SELECT interval '-infinity' < interval '-infinity';
+SELECT interval 'infinity' <= interval 'infinity';
+SELECT interval 'infinity' <= interval '-infinity';
+SELECT interval '-infinity' <= interval 'infinity';
+SELECT interval '-infinity' <= interval '-infinity';
+SELECT interval 'infinity' > interval 'infinity';
+SELECT interval 'infinity' > interval '-infinity';
+SELECT interval '-infinity' > interval 'infinity';
+SELECT interval '-infinity' > interval '-infinity';
+SELECT interval 'infinity' >= interval 'infinity';
+SELECT interval 'infinity' >= interval '-infinity';
+SELECT interval '-infinity' >= interval 'infinity';
+SELECT interval '-infinity' >= interval '-infinity';
+SELECT interval 'infinity' = interval 'infinity';
+SELECT interval 'infinity' = interval '-infinity';
+SELECT interval '-infinity' = interval 'infinity';
+SELECT interval '-infinity' = interval '-infinity';
+SELECT interval 'infinity' <> interval 'infinity';
+SELECT interval 'infinity' <> interval '-infinity';
+SELECT interval '-infinity' <> interval 'infinity';
+SELECT interval '-infinity' <> interval '-infinity';
+
+SELECT -interval 'infinity';
+SELECT -interval '-infinity';
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 2;
+SELECT interval 'infinity' * -2;
+SELECT interval '-infinity' * 2;
+SELECT interval '-infinity' * -2;
+SELECT interval 'infinity' * 'infinity';
+SELECT interval 'infinity' * '-infinity';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'infinity';
+SELECT interval '-infinity' * '-infinity';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 3;
+SELECT interval 'infinity' / -3;
+SELECT interval '-infinity' / 3;
+SELECT interval '-infinity' / -3;
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_trunc('hour', interval 'infinity');
+SELECT date_trunc('hour', interval '-infinity');
+
+SELECT date_part('us', interval 'infinity');
+SELECT date_part('us', interval '-infinity');
+SELECT date_part('ms', interval 'infinity');
+SELECT date_part('ms', interval '-infinity');
+SELECT date_part('second', interval 'infinity');
+SELECT date_part('second', interval '-infinity');
+SELECT date_part('minute', interval 'infinity');
+SELECT date_part('minute', interval '-infinity');
+SELECT date_part('hour', interval 'infinity');
+SELECT date_part('hour', interval '-infinity');
+SELECT date_part('day', interval 'infinity');
+SELECT date_part('day', interval '-infinity');
+SELECT date_part('month', interval 'infinity');
+SELECT date_part('month', interval '-infinity');
+SELECT date_part('quarter', interval 'infinity');
+SELECT date_part('quarter', interval '-infinity');
+SELECT date_part('year', interval 'infinity');
+SELECT date_part('year', interval '-infinity');
+SELECT date_part('decade', interval 'infinity');
+SELECT date_part('decade', interval '-infinity');
+SELECT date_part('century', interval 'infinity');
+SELECT date_part('century', interval '-infinity');
+SELECT date_part('millennium', interval 'infinity');
+SELECT date_part('millennium', interval '-infinity');
+SELECT date_part('epoch', interval 'infinity');
+SELECT date_part('epoch', interval '-infinity');
+SELECT extract(us from interval 'infinity');
+SELECT extract(us from interval '-infinity');
+SELECT extract(ms from interval 'infinity');
+SELECT extract(ms from interval '-infinity');
+SELECT extract(second from interval 'infinity');
+SELECT extract(second from interval '-infinity');
+SELECT extract(minute from interval 'infinity');
+SELECT extract(minute from interval '-infinity');
+SELECT extract(hour from interval 'infinity');
+SELECT extract(hour from interval '-infinity');
+SELECT extract(day from interval 'infinity');
+SELECT extract(day from interval '-infinity');
+SELECT extract(month from interval 'infinity');
+SELECT extract(month from interval '-infinity');
+SELECT extract(quarter from interval 'infinity');
+SELECT extract(quarter from interval '-infinity');
+SELECT extract(year from interval 'infinity');
+SELECT extract(year from interval '-infinity');
+SELECT extract(decade from interval 'infinity');
+SELECT extract(decade from interval '-infinity');
+SELECT extract(century from interval 'infinity');
+SELECT extract(century from interval '-infinity');
+SELECT extract(millennium from interval 'infinity');
+SELECT extract(millennium from interval '-infinity');
+SELECT extract(epoch from interval 'infinity');
+SELECT extract(epoch from interval '-infinity');
+
+SELECT justify_days(interval 'infinity');
+SELECT justify_days(interval '-infinity');
+SELECT justify_hours(interval 'infinity');
+SELECT justify_hours(interval '-infinity');
+SELECT justify_interval(interval 'infinity');
+SELECT justify_interval(interval '-infinity');
-- 
2.34.1

diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 82f3180221..1fd99c53d4 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -652,30 +652,31 @@ SELECT timetz '11:27:42' + interval '-infinity';
 SELECT timetz '11:27:42' - interval 'infinity';
 SELECT timetz '11:27:42' - interval '-infinity';
 
-SELECT interval 'infinity' < interval 'infinity';
-SELECT interval 'infinity' < interval '-infinity';
-SELECT interval '-infinity' < interval 'infinity';
-SELECT interval '-infinity' < interval '-infinity';
-SELECT interval 'infinity' <= interval 'infinity';
-SELECT interval 'infinity' <= interval '-infinity';
-SELECT interval '-infinity' <= interval 'infinity';
-SELECT interval '-infinity' <= interval '-infinity';
-SELECT interval 'infinity' > interval 'infinity';
-SELECT interval 'infinity' > interval '-infinity';
-SELECT interval '-infinity' > interval 'infinity';
-SELECT interval '-infinity' > interval '-infinity';
-SELECT interval 'infinity' >= interval 'infinity';
-SELECT interval 'infinity' >= interval '-infinity';
-SELECT interval '-infinity' >= interval 'infinity';
-SELECT interval '-infinity' >= interval '-infinity';
-SELECT interval 'infinity' = interval 'infinity';
-SELECT interval 'infinity' = interval '-infinity';
-SELECT interval '-infinity' = interval 'infinity';
-SELECT interval '-infinity' = interval '-infinity';
-SELECT interval 'infinity' <> interval 'infinity';
-SELECT interval 'infinity' <> interval '-infinity';
-SELECT interval '-infinity' <> interval 'infinity';
-SELECT interval '-infinity' <> interval '-infinity';
+DO $$
+DECLARE
+    intv interval;
+    intv1 interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    OPERATOR text[] := '{<,<=,=, >,>=,<>}';
+    opr text;
+    result boolean;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH opr IN ARRAY OPERATOR LOOP
+            FOREACH intv1 IN ARRAY intvs LOOP
+                EXECUTE 'select interval ' || quote_literal(intv) || ' ' 
+                  || opr || ' interval ' || quote_literal(intv1) INTO result;
+                RAISE NOTICE '%'
+                  ,(format('%10s %2s %10s %2s'
+                  ,intv
+                  ,opr
+                  ,intv1
+                  ,result));
+            END LOOP;
+        END LOOP;
+    END LOOP;
+END
+$$;
 
 SELECT -interval 'infinity';
 SELECT -interval '-infinity';
@@ -709,58 +710,48 @@ SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02
 SELECT date_trunc('hour', interval 'infinity');
 SELECT date_trunc('hour', interval '-infinity');
 
-SELECT date_part('us', interval 'infinity');
-SELECT date_part('us', interval '-infinity');
-SELECT date_part('ms', interval 'infinity');
-SELECT date_part('ms', interval '-infinity');
-SELECT date_part('second', interval 'infinity');
-SELECT date_part('second', interval '-infinity');
-SELECT date_part('minute', interval 'infinity');
-SELECT date_part('minute', interval '-infinity');
-SELECT date_part('hour', interval 'infinity');
-SELECT date_part('hour', interval '-infinity');
-SELECT date_part('day', interval 'infinity');
-SELECT date_part('day', interval '-infinity');
-SELECT date_part('month', interval 'infinity');
-SELECT date_part('month', interval '-infinity');
-SELECT date_part('quarter', interval 'infinity');
-SELECT date_part('quarter', interval '-infinity');
-SELECT date_part('year', interval 'infinity');
-SELECT date_part('year', interval '-infinity');
-SELECT date_part('decade', interval 'infinity');
-SELECT date_part('decade', interval '-infinity');
-SELECT date_part('century', interval 'infinity');
-SELECT date_part('century', interval '-infinity');
-SELECT date_part('millennium', interval 'infinity');
-SELECT date_part('millennium', interval '-infinity');
-SELECT date_part('epoch', interval 'infinity');
-SELECT date_part('epoch', interval '-infinity');
-SELECT extract(us from interval 'infinity');
-SELECT extract(us from interval '-infinity');
-SELECT extract(ms from interval 'infinity');
-SELECT extract(ms from interval '-infinity');
-SELECT extract(second from interval 'infinity');
-SELECT extract(second from interval '-infinity');
-SELECT extract(minute from interval 'infinity');
-SELECT extract(minute from interval '-infinity');
-SELECT extract(hour from interval 'infinity');
-SELECT extract(hour from interval '-infinity');
-SELECT extract(day from interval 'infinity');
-SELECT extract(day from interval '-infinity');
-SELECT extract(month from interval 'infinity');
-SELECT extract(month from interval '-infinity');
-SELECT extract(quarter from interval 'infinity');
-SELECT extract(quarter from interval '-infinity');
-SELECT extract(year from interval 'infinity');
-SELECT extract(year from interval '-infinity');
-SELECT extract(decade from interval 'infinity');
-SELECT extract(decade from interval '-infinity');
-SELECT extract(century from interval 'infinity');
-SELECT extract(century from interval '-infinity');
-SELECT extract(millennium from interval 'infinity');
-SELECT extract(millennium from interval '-infinity');
-SELECT extract(epoch from interval 'infinity');
-SELECT extract(epoch from interval '-infinity');
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result double precision;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select date_part( ' || quote_literal(unit) || ' ,interval ' 
+                     || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('date_part(%10s, interval %10s) yiled', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
+
+
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result numeric;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select extract( ' || quote_literal(unit) 
+               || ' from interval ' || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('extract(%10s from interval %9s) yiled', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
 
 SELECT justify_days(interval 'infinity');
 SELECT justify_days(interval '-infinity');

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 9484b29ec4..350363b9ad 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -2973,21 +2973,21 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	 * timestamp with the same sign. Adding two infintes with different signs
 	 * results in an error.
 	 */
-	/* TODO this logic can probably be combined and cleaned up. */
-	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
-		TIMESTAMP_NOBEGIN(result);
-	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
-		TIMESTAMP_NOEND(result);
-	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot add infinite values with opposite signs")));
-	else if (INTERVAL_IS_NOBEGIN(span))
-		TIMESTAMP_NOBEGIN(result);
-	else if (INTERVAL_IS_NOEND(span))
-		TIMESTAMP_NOEND(result);
-	else if (TIMESTAMP_NOT_FINITE(timestamp))
-		result = timestamp;
+	if (	(INTERVAL_IS_NOBEGIN(span)     && TIMESTAMP_IS_NOBEGIN(timestamp))
+    	|| (INTERVAL_IS_NOBEGIN(span)     && !TIMESTAMP_NOT_FINITE(timestamp))
+    	|| (!INTERVAL_NOT_FINITE(span)    &&	TIMESTAMP_IS_NOBEGIN(timestamp)))
+    			TIMESTAMP_NOBEGIN(result);
+
+	else if ((INTERVAL_IS_NOEND(span)    && TIMESTAMP_IS_NOEND(timestamp))
+    	|| (INTERVAL_IS_NOEND(span)    && !TIMESTAMP_NOT_FINITE(timestamp))
+    	||(!INTERVAL_NOT_FINITE(span) &&	TIMESTAMP_IS_NOEND(timestamp)))
+    			TIMESTAMP_NOEND(result);
+				
+	else if ((!INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		|| (INTERVAL_NOT_FINITE(span) && !TIMESTAMP_NOT_FINITE(timestamp)))
+    		ereport(ERROR,
+    			(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+        		errmsg("cannot add infinite values with opposite signs")));
 	else
 	{
 		if (span->month != 0)
@@ -3095,21 +3095,21 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	 * timestamp with the same sign. Adding two infintes with different signs
 	 * results in an error.
 	 */
-	/* TODO this logic can probably be combined and cleaned up. */
-	if (INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
-		TIMESTAMP_NOBEGIN(result);
-	else if (INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
-		TIMESTAMP_NOEND(result);
-	else if (INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot add infinite values with opposite signs")));
-	else if (INTERVAL_IS_NOBEGIN(span))
-		TIMESTAMP_NOBEGIN(result);
-	else if (INTERVAL_IS_NOEND(span))
-		TIMESTAMP_NOEND(result);
-	else if (TIMESTAMP_NOT_FINITE(timestamp))
-		result = timestamp;
+	if ((INTERVAL_IS_NOBEGIN(span)     && TIMESTAMP_IS_NOBEGIN(timestamp))
+    || (INTERVAL_IS_NOBEGIN(span)     && !TIMESTAMP_NOT_FINITE(timestamp))
+    || (!INTERVAL_NOT_FINITE(span)    &&  TIMESTAMP_IS_NOBEGIN(timestamp)))
+        TIMESTAMP_NOBEGIN(result);
+    
+    else if ((INTERVAL_IS_NOEND(span)   && TIMESTAMP_IS_NOEND(timestamp))
+    	|| (INTERVAL_IS_NOEND(span)    && !TIMESTAMP_NOT_FINITE(timestamp))
+    	|| (!INTERVAL_NOT_FINITE(span) &&  TIMESTAMP_IS_NOEND(timestamp)))
+        	TIMESTAMP_NOEND(result);
+
+    else if ((!INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+		|| (INTERVAL_NOT_FINITE(span) && !TIMESTAMP_NOT_FINITE(timestamp)))
+        	ereport(ERROR,
+            	(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                	errmsg("cannot add infinite values with opposite signs")));
 	else
 	{
 		if (span->month != 0)
@@ -3255,61 +3255,52 @@ interval_pl(PG_FUNCTION_ARGS)
 	 * infinite interval with the same sign. Adding two infinte intervals with
 	 * different signs results in an error.
 	 */
-	/* TODO can be combined and simplified */
-	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2))
-	{
-		INTERVAL_NOBEGIN(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
-	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2))
-	{
-		INTERVAL_NOEND(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
+	if ((INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2))
+      ||(INTERVAL_IS_NOBEGIN(span1) && !INTERVAL_NOT_FINITE(span2))
+      ||(!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOBEGIN(span2)))
+	        INTERVAL_NOBEGIN(result);
+
+	else if
+        ((INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2))
+      	||(INTERVAL_IS_NOEND(span1) && !INTERVAL_NOT_FINITE(span2))
+    	||(!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOEND(span2)))
+		    INTERVAL_NOEND(result);
+
 	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("cannot add infinite values with opposite signs")));
 	}
-	else if (INTERVAL_NOT_FINITE(span1))
-	{
-		memcpy(result, span1, sizeof(Interval));
-		PG_RETURN_INTERVAL_P(result);
-	}
-	else if (INTERVAL_NOT_FINITE(span2))
+	else
 	{
-		memcpy(result, span2, sizeof(Interval));
-		PG_RETURN_INTERVAL_P(result);
-	}
-
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
 
-	if (INTERVAL_NOT_FINITE(result))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3327,61 +3318,51 @@ interval_mi(PG_FUNCTION_ARGS)
 	 * infinite interval with the same sign as the left operand. Subtracting
 	 * two infinte intervals with the same sign results in an error.
 	 */
-	/* TODO can be simplified and cleaned up */
-	if (INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2))
-	{
-		INTERVAL_NOBEGIN(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
-	else if (INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2))
-	{
-		INTERVAL_NOEND(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
+	if ((INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2))
+      ||(INTERVAL_IS_NOBEGIN(span1) && !INTERVAL_NOT_FINITE(span2))
+      ||(!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOEND(span2)))
+		    INTERVAL_NOBEGIN(result);
+
+	else if ((INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2))
+    	||(INTERVAL_IS_NOEND(span1) && !INTERVAL_NOT_FINITE(span2))
+		||(!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOBEGIN(span2)))
+	    	INTERVAL_NOEND(result);
+	
 	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("cannot subtract infinite values with the same signs")));
-	}
-	else if (INTERVAL_NOT_FINITE(span1))
-	{
-		memcpy(result, span1, sizeof(Interval));
-		PG_RETURN_INTERVAL_P(result);
-	}
-	else if (INTERVAL_NOT_FINITE(span2))
+	}	
+	else
 	{
-		memcpy(result, span2, sizeof(Interval));
-		PG_RETURN_INTERVAL_P(result);
-	}
-
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
 
-	if (INTERVAL_NOT_FINITE(result))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 82f3180221..1fd99c53d4 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -652,30 +652,31 @@ SELECT timetz '11:27:42' + interval '-infinity';
 SELECT timetz '11:27:42' - interval 'infinity';
 SELECT timetz '11:27:42' - interval '-infinity';
 
-SELECT interval 'infinity' < interval 'infinity';
-SELECT interval 'infinity' < interval '-infinity';
-SELECT interval '-infinity' < interval 'infinity';
-SELECT interval '-infinity' < interval '-infinity';
-SELECT interval 'infinity' <= interval 'infinity';
-SELECT interval 'infinity' <= interval '-infinity';
-SELECT interval '-infinity' <= interval 'infinity';
-SELECT interval '-infinity' <= interval '-infinity';
-SELECT interval 'infinity' > interval 'infinity';
-SELECT interval 'infinity' > interval '-infinity';
-SELECT interval '-infinity' > interval 'infinity';
-SELECT interval '-infinity' > interval '-infinity';
-SELECT interval 'infinity' >= interval 'infinity';
-SELECT interval 'infinity' >= interval '-infinity';
-SELECT interval '-infinity' >= interval 'infinity';
-SELECT interval '-infinity' >= interval '-infinity';
-SELECT interval 'infinity' = interval 'infinity';
-SELECT interval 'infinity' = interval '-infinity';
-SELECT interval '-infinity' = interval 'infinity';
-SELECT interval '-infinity' = interval '-infinity';
-SELECT interval 'infinity' <> interval 'infinity';
-SELECT interval 'infinity' <> interval '-infinity';
-SELECT interval '-infinity' <> interval 'infinity';
-SELECT interval '-infinity' <> interval '-infinity';
+DO $$
+DECLARE
+    intv interval;
+    intv1 interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    OPERATOR text[] := '{<,<=,=, >,>=,<>}';
+    opr text;
+    result boolean;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH opr IN ARRAY OPERATOR LOOP
+            FOREACH intv1 IN ARRAY intvs LOOP
+                EXECUTE 'select interval ' || quote_literal(intv) || ' ' 
+                  || opr || ' interval ' || quote_literal(intv1) INTO result;
+                RAISE NOTICE '%'
+                  ,(format('%10s %2s %10s %2s'
+                  ,intv
+                  ,opr
+                  ,intv1
+                  ,result));
+            END LOOP;
+        END LOOP;
+    END LOOP;
+END
+$$;
 
 SELECT -interval 'infinity';
 SELECT -interval '-infinity';
@@ -709,58 +710,48 @@ SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02
 SELECT date_trunc('hour', interval 'infinity');
 SELECT date_trunc('hour', interval '-infinity');
 
-SELECT date_part('us', interval 'infinity');
-SELECT date_part('us', interval '-infinity');
-SELECT date_part('ms', interval 'infinity');
-SELECT date_part('ms', interval '-infinity');
-SELECT date_part('second', interval 'infinity');
-SELECT date_part('second', interval '-infinity');
-SELECT date_part('minute', interval 'infinity');
-SELECT date_part('minute', interval '-infinity');
-SELECT date_part('hour', interval 'infinity');
-SELECT date_part('hour', interval '-infinity');
-SELECT date_part('day', interval 'infinity');
-SELECT date_part('day', interval '-infinity');
-SELECT date_part('month', interval 'infinity');
-SELECT date_part('month', interval '-infinity');
-SELECT date_part('quarter', interval 'infinity');
-SELECT date_part('quarter', interval '-infinity');
-SELECT date_part('year', interval 'infinity');
-SELECT date_part('year', interval '-infinity');
-SELECT date_part('decade', interval 'infinity');
-SELECT date_part('decade', interval '-infinity');
-SELECT date_part('century', interval 'infinity');
-SELECT date_part('century', interval '-infinity');
-SELECT date_part('millennium', interval 'infinity');
-SELECT date_part('millennium', interval '-infinity');
-SELECT date_part('epoch', interval 'infinity');
-SELECT date_part('epoch', interval '-infinity');
-SELECT extract(us from interval 'infinity');
-SELECT extract(us from interval '-infinity');
-SELECT extract(ms from interval 'infinity');
-SELECT extract(ms from interval '-infinity');
-SELECT extract(second from interval 'infinity');
-SELECT extract(second from interval '-infinity');
-SELECT extract(minute from interval 'infinity');
-SELECT extract(minute from interval '-infinity');
-SELECT extract(hour from interval 'infinity');
-SELECT extract(hour from interval '-infinity');
-SELECT extract(day from interval 'infinity');
-SELECT extract(day from interval '-infinity');
-SELECT extract(month from interval 'infinity');
-SELECT extract(month from interval '-infinity');
-SELECT extract(quarter from interval 'infinity');
-SELECT extract(quarter from interval '-infinity');
-SELECT extract(year from interval 'infinity');
-SELECT extract(year from interval '-infinity');
-SELECT extract(decade from interval 'infinity');
-SELECT extract(decade from interval '-infinity');
-SELECT extract(century from interval 'infinity');
-SELECT extract(century from interval '-infinity');
-SELECT extract(millennium from interval 'infinity');
-SELECT extract(millennium from interval '-infinity');
-SELECT extract(epoch from interval 'infinity');
-SELECT extract(epoch from interval '-infinity');
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result double precision;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select date_part( ' || quote_literal(unit) || ' ,interval ' 
+                     || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('date_part(%10s, interval %10s) yiled', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
+
+
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result numeric;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select extract( ' || quote_literal(unit) 
+               || ' from interval ' || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('extract(%10s from interval %9s) yiled', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
 
 SELECT justify_days(interval 'infinity');
 SELECT justify_days(interval '-infinity');

From 4bf672f9079322cffde635dff2078582fca55f09 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

TODOs
1. Various TODOs in code.
2. Correctly implement interval_part for infinite intervals.
3. Fix Tests.
4. Should we just use the months field to test for infinity?
5. Update docs

Ashutosh Bapat and Joe Koshakow
---
 src/backend/utils/adt/date.c           |  20 +
 src/backend/utils/adt/datetime.c       |  14 +-
 src/backend/utils/adt/timestamp.c      | 425 ++++++++++++---
 src/include/datatype/timestamp.h       |  22 +
 src/test/regress/expected/horology.out |   6 +-
 src/test/regress/expected/interval.out | 691 +++++++++++++++++++++++--
 src/test/regress/sql/horology.sql      |   6 +-
 src/test/regress/sql/interval.sql      | 191 ++++++-
 8 files changed, 1264 insertions(+), 111 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 99171d9c92..8334b9053f 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2067,6 +2067,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2090,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2609,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2636,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index d166613895..4192e7a74b 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -70,7 +70,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -978,7 +978,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1928,7 +1928,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -3233,7 +3233,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3635,6 +3635,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4040,7 +4042,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4919,7 +4921,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 928c330897..87277f2f3b 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void negate_interval(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2027,6 +2060,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2044,6 +2079,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2077,7 +2114,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2769,6 +2808,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2844,6 +2886,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2882,6 +2927,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2920,8 +2968,26 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
-		result = timestamp;
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if ((INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		|| (INTERVAL_IS_NOBEGIN(span) && !TIMESTAMP_NOT_FINITE(timestamp))
+		|| (!INTERVAL_NOT_FINITE(span) && TIMESTAMP_IS_NOBEGIN(timestamp)))
+		TIMESTAMP_NOBEGIN(result);
+
+	else if ((INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+			 || (INTERVAL_IS_NOEND(span) && !TIMESTAMP_NOT_FINITE(timestamp))
+			 || (!INTERVAL_NOT_FINITE(span) && TIMESTAMP_IS_NOEND(timestamp)))
+		TIMESTAMP_NOEND(result);
+
+	else if ((!INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+			 || (INTERVAL_NOT_FINITE(span) && !TIMESTAMP_NOT_FINITE(timestamp)))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite values with opposite signs")));
 	else
 	{
 		if (span->month != 0)
@@ -2999,9 +3065,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3026,8 +3090,26 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
-		result = timestamp;
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if ((INTERVAL_IS_NOBEGIN(span) && TIMESTAMP_IS_NOBEGIN(timestamp))
+		|| (INTERVAL_IS_NOBEGIN(span) && !TIMESTAMP_NOT_FINITE(timestamp))
+		|| (!INTERVAL_NOT_FINITE(span) && TIMESTAMP_IS_NOBEGIN(timestamp)))
+		TIMESTAMP_NOBEGIN(result);
+
+	else if ((INTERVAL_IS_NOEND(span) && TIMESTAMP_IS_NOEND(timestamp))
+			 || (INTERVAL_IS_NOEND(span) && !TIMESTAMP_NOT_FINITE(timestamp))
+			 || (!INTERVAL_NOT_FINITE(span) && TIMESTAMP_IS_NOEND(timestamp)))
+		TIMESTAMP_NOEND(result);
+
+	else if ((!INTERVAL_NOT_FINITE(span) && TIMESTAMP_NOT_FINITE(timestamp))
+			 || (INTERVAL_NOT_FINITE(span) && !TIMESTAMP_NOT_FINITE(timestamp)))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite values with opposite signs")));
 	else
 	{
 		if (span->month != 0)
@@ -3109,9 +3191,7 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	negate_interval(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3126,23 +3206,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	negate_interval(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3186,28 +3250,57 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if ((INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOBEGIN(span2))
+		|| (INTERVAL_IS_NOBEGIN(span1) && !INTERVAL_NOT_FINITE(span2))
+		|| (!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOBEGIN(span2)))
+		INTERVAL_NOBEGIN(result);
+
+	else if
+			((INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOEND(span2))
+			 || (INTERVAL_IS_NOEND(span1) && !INTERVAL_NOT_FINITE(span2))
+			 || (!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOEND(span2)))
+		INTERVAL_NOEND(result);
+
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("cannot add infinite values with opposite signs")));
+	}
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3220,28 +3313,56 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if ((INTERVAL_IS_NOBEGIN(span1) && INTERVAL_IS_NOEND(span2))
+		|| (INTERVAL_IS_NOBEGIN(span1) && !INTERVAL_NOT_FINITE(span2))
+		|| (!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOEND(span2)))
+		INTERVAL_NOBEGIN(result);
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	else if ((INTERVAL_IS_NOEND(span1) && INTERVAL_IS_NOBEGIN(span2))
+			 || (INTERVAL_IS_NOEND(span1) && !INTERVAL_NOT_FINITE(span2))
+			 || (!INTERVAL_NOT_FINITE(span1) && INTERVAL_IS_NOBEGIN(span2)))
+		INTERVAL_NOEND(result);
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	else if (INTERVAL_NOT_FINITE(span1) && INTERVAL_NOT_FINITE(span2))
+	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("cannot subtract infinite values with the same signs")));
+	}
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3265,6 +3386,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3325,6 +3464,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3356,6 +3500,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			negate_interval(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3377,6 +3544,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3910,6 +4082,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4365,6 +4542,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5224,6 +5407,62 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+/*  TODO I don't actaully know if this is correct. */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	/* TODO: Maybe everything should be returning inf/-inf? */
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5247,6 +5486,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteTimestampTzPart(type, val, lowunits,
+												 INTERVAL_IS_NOBEGIN(interval),
+												 false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5949,3 +6216,33 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 		SRF_RETURN_DONE(funcctx);
 	}
 }
+
+/*
+ * TODO: possibly we should move these to a place along with other interval_*
+ * functions.
+ */
+
+/* Negates the given interval */
+static void
+negate_interval(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 21a37e21e9..ba9f39a445 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,28 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*  TODO: Should we make custom NOBEGIN and NOEND constants for Interval? */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = DT_NOBEGIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == DT_NOBEGIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = DT_NOEND;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == DT_NOEND && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..84b4dd920a 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -72,6 +86,10 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
 ERROR:  invalid input syntax for type interval: "@ 30 eons ago"
 LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
                                               ^
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+ERROR:  invalid input syntax for type interval: "+infinity"
+LINE 1: INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
+                                              ^
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
  pg_input_is_valid 
@@ -117,7 +135,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +152,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +163,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +173,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +192,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +208,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +217,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +253,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +262,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +272,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +433,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +869,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +881,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1578,31 +1629,31 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1732,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |      |     |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        |      |     |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1820,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1831,571 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+SELECT isfinite(interval 'infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT isfinite(interval '-infinity');
+ isfinite 
+----------
+ f
+(1 row)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  cannot subtract infinite values with the same signs
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  cannot subtract infinite values with the same signs
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+DO $$
+DECLARE
+    intv interval;
+    intv1 interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    OPERATOR text[] := '{<,<=,=, >,>=,<>}';
+    opr text;
+    result boolean;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH opr IN ARRAY OPERATOR LOOP
+            FOREACH intv1 IN ARRAY intvs LOOP
+                EXECUTE 'select interval ' || quote_literal(intv) || ' ' 
+                  || opr || ' interval ' || quote_literal(intv1) INTO result;
+                RAISE NOTICE '%'
+                  ,(format('%10s %2s %10s %2s'
+                  ,intv
+                  ,opr
+                  ,intv1
+                  ,result));
+            END LOOP;
+        END LOOP;
+    END LOOP;
+END
+$$;
+NOTICE:    infinity  <   infinity  f
+NOTICE:    infinity  <  -infinity  f
+NOTICE:    infinity <=   infinity  t
+NOTICE:    infinity <=  -infinity  f
+NOTICE:    infinity  =   infinity  t
+NOTICE:    infinity  =  -infinity  f
+NOTICE:    infinity  >   infinity  f
+NOTICE:    infinity  >  -infinity  t
+NOTICE:    infinity >=   infinity  t
+NOTICE:    infinity >=  -infinity  t
+NOTICE:    infinity <>   infinity  f
+NOTICE:    infinity <>  -infinity  t
+NOTICE:   -infinity  <   infinity  t
+NOTICE:   -infinity  <  -infinity  f
+NOTICE:   -infinity <=   infinity  t
+NOTICE:   -infinity <=  -infinity  t
+NOTICE:   -infinity  =   infinity  f
+NOTICE:   -infinity  =  -infinity  t
+NOTICE:   -infinity  >   infinity  f
+NOTICE:   -infinity  >  -infinity  f
+NOTICE:   -infinity >=   infinity  f
+NOTICE:   -infinity >=  -infinity  t
+NOTICE:   -infinity <>   infinity  t
+NOTICE:   -infinity <>  -infinity  f
+SELECT -interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT -interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * -2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * 2;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * -2;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' * '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' * '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / -3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / 3;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' / -3;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_trunc('hour', interval 'infinity');
+ date_trunc 
+------------
+ infinity
+(1 row)
+
+SELECT date_trunc('hour', interval '-infinity');
+ date_trunc 
+------------
+ -infinity
+(1 row)
+
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result double precision;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select date_part( ' || quote_literal(unit) || ' ,interval ' 
+                     || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('date_part(%10s, interval %10s) yield', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
+NOTICE:  date_part(        us, interval   infinity) yield <NULL>
+NOTICE:  date_part(        ms, interval   infinity) yield <NULL>
+NOTICE:  date_part(    second, interval   infinity) yield <NULL>
+NOTICE:  date_part(    minute, interval   infinity) yield <NULL>
+NOTICE:  date_part(      hour, interval   infinity) yield <NULL>
+NOTICE:  date_part(       day, interval   infinity) yield <NULL>
+NOTICE:  date_part(     month, interval   infinity) yield <NULL>
+NOTICE:  date_part(   quarter, interval   infinity) yield <NULL>
+NOTICE:  date_part(      year, interval   infinity) yield Infinity
+NOTICE:  date_part(    decade, interval   infinity) yield Infinity
+NOTICE:  date_part(   century, interval   infinity) yield Infinity
+NOTICE:  date_part(millennium, interval   infinity) yield Infinity
+NOTICE:  date_part(     epoch, interval   infinity) yield Infinity
+NOTICE:  date_part(        us, interval  -infinity) yield <NULL>
+NOTICE:  date_part(        ms, interval  -infinity) yield <NULL>
+NOTICE:  date_part(    second, interval  -infinity) yield <NULL>
+NOTICE:  date_part(    minute, interval  -infinity) yield <NULL>
+NOTICE:  date_part(      hour, interval  -infinity) yield <NULL>
+NOTICE:  date_part(       day, interval  -infinity) yield <NULL>
+NOTICE:  date_part(     month, interval  -infinity) yield <NULL>
+NOTICE:  date_part(   quarter, interval  -infinity) yield <NULL>
+NOTICE:  date_part(      year, interval  -infinity) yield -Infinity
+NOTICE:  date_part(    decade, interval  -infinity) yield -Infinity
+NOTICE:  date_part(   century, interval  -infinity) yield -Infinity
+NOTICE:  date_part(millennium, interval  -infinity) yield -Infinity
+NOTICE:  date_part(     epoch, interval  -infinity) yield -Infinity
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result numeric;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select extract( ' || quote_literal(unit) 
+               || ' from interval ' || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('extract(%10s from interval %9s) yield', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
+NOTICE:  extract(        us from interval  infinity) yield <NULL>
+NOTICE:  extract(        ms from interval  infinity) yield <NULL>
+NOTICE:  extract(    second from interval  infinity) yield <NULL>
+NOTICE:  extract(    minute from interval  infinity) yield <NULL>
+NOTICE:  extract(      hour from interval  infinity) yield <NULL>
+NOTICE:  extract(       day from interval  infinity) yield <NULL>
+NOTICE:  extract(     month from interval  infinity) yield <NULL>
+NOTICE:  extract(   quarter from interval  infinity) yield <NULL>
+NOTICE:  extract(      year from interval  infinity) yield Infinity
+NOTICE:  extract(    decade from interval  infinity) yield Infinity
+NOTICE:  extract(   century from interval  infinity) yield Infinity
+NOTICE:  extract(millennium from interval  infinity) yield Infinity
+NOTICE:  extract(     epoch from interval  infinity) yield Infinity
+NOTICE:  extract(        us from interval -infinity) yield <NULL>
+NOTICE:  extract(        ms from interval -infinity) yield <NULL>
+NOTICE:  extract(    second from interval -infinity) yield <NULL>
+NOTICE:  extract(    minute from interval -infinity) yield <NULL>
+NOTICE:  extract(      hour from interval -infinity) yield <NULL>
+NOTICE:  extract(       day from interval -infinity) yield <NULL>
+NOTICE:  extract(     month from interval -infinity) yield <NULL>
+NOTICE:  extract(   quarter from interval -infinity) yield <NULL>
+NOTICE:  extract(      year from interval -infinity) yield -Infinity
+NOTICE:  extract(    decade from interval -infinity) yield -Infinity
+NOTICE:  extract(   century from interval -infinity) yield -Infinity
+NOTICE:  extract(millennium from interval -infinity) yield -Infinity
+NOTICE:  extract(     epoch from interval -infinity) yield -Infinity
+SELECT justify_days(interval 'infinity');
+ justify_days 
+--------------
+ infinity
+(1 row)
+
+SELECT justify_days(interval '-infinity');
+ justify_days 
+--------------
+ -infinity
+(1 row)
+
+SELECT justify_hours(interval 'infinity');
+ justify_hours 
+---------------
+ infinity
+(1 row)
+
+SELECT justify_hours(interval '-infinity');
+ justify_hours 
+---------------
+ -infinity
+(1 row)
+
+SELECT justify_interval(interval 'infinity');
+ justify_interval 
+------------------
+ infinity
+(1 row)
+
+SELECT justify_interval(interval '-infinity');
+ justify_interval 
+------------------
+ -infinity
+(1 row)
+
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..51195d71d1 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,10 +29,13 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 30 eons ago');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('+infinity');
 
 -- Test non-error-throwing API
 SELECT pg_input_is_valid('1.5 weeks', 'interval');
@@ -140,7 +145,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -509,13 +514,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +583,179 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+SELECT isfinite(interval 'infinity');
+SELECT isfinite(interval '-infinity');
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+DO $$
+DECLARE
+    intv interval;
+    intv1 interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    OPERATOR text[] := '{<,<=,=, >,>=,<>}';
+    opr text;
+    result boolean;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH opr IN ARRAY OPERATOR LOOP
+            FOREACH intv1 IN ARRAY intvs LOOP
+                EXECUTE 'select interval ' || quote_literal(intv) || ' ' 
+                  || opr || ' interval ' || quote_literal(intv1) INTO result;
+                RAISE NOTICE '%'
+                  ,(format('%10s %2s %10s %2s'
+                  ,intv
+                  ,opr
+                  ,intv1
+                  ,result));
+            END LOOP;
+        END LOOP;
+    END LOOP;
+END
+$$;
+
+SELECT -interval 'infinity';
+SELECT -interval '-infinity';
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 2;
+SELECT interval 'infinity' * -2;
+SELECT interval '-infinity' * 2;
+SELECT interval '-infinity' * -2;
+SELECT interval 'infinity' * 'infinity';
+SELECT interval 'infinity' * '-infinity';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'infinity';
+SELECT interval '-infinity' * '-infinity';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 3;
+SELECT interval 'infinity' / -3;
+SELECT interval '-infinity' / 3;
+SELECT interval '-infinity' / -3;
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_trunc('hour', interval 'infinity');
+SELECT date_trunc('hour', interval '-infinity');
+
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result double precision;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select date_part( ' || quote_literal(unit) || ' ,interval ' 
+                     || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('date_part(%10s, interval %10s) yield', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
+
+
+DO $$
+DECLARE
+    intv interval;
+    intvs interval[] := '{+infinity,-infinity}';
+    units text[] := '{us,ms,second,minute,hour,day,month
+            ,quarter,year,decade,century,millennium,epoch}';
+    unit text;
+    result numeric;
+BEGIN
+    FOREACH intv IN ARRAY intvs LOOP
+        FOREACH unit IN ARRAY units LOOP
+            EXECUTE 'select extract( ' || quote_literal(unit) 
+               || ' from interval ' || quote_literal(intv) || ' )' INTO result;
+            RAISE NOTICE '% %'
+               ,(format('extract(%10s from interval %9s) yield', unit, intv))
+               ,result;
+        END LOOP;
+    END LOOP;
+END
+$$;
+
+SELECT justify_days(interval 'infinity');
+SELECT justify_days(interval '-infinity');
+SELECT justify_hours(interval 'infinity');
+SELECT justify_hours(interval '-infinity');
+SELECT justify_interval(interval 'infinity');
+SELECT justify_interval(interval '-infinity');
-- 
2.34.1

From 4ea7c98d47dcbff1313a5013572cc79839e4417e Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

TODOs
1. Should we just use the months field to test for infinity?
2. Should the error messages for adding different sign infinties be "interval out of range"?

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml             |   2 +-
 doc/src/sgml/func.sgml                 |   5 +-
 src/backend/utils/adt/date.c           |  20 ++
 src/backend/utils/adt/datetime.c       |  14 +-
 src/backend/utils/adt/timestamp.c      | 448 ++++++++++++++++++++----
 src/include/datatype/timestamp.h       |  21 ++
 src/test/regress/expected/horology.out |   6 +-
 src/test/regress/expected/interval.out | 466 +++++++++++++++++++++++--
 src/test/regress/sql/horology.sql      |   6 +-
 src/test/regress/sql/interval.sql      | 130 ++++++-
 10 files changed, 1002 insertions(+), 116 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index fdffba4442..2bcf959f70 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2316,7 +2316,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 3bf8d021c3..7ddf76da4a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9369,7 +9369,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10256,7 +10256,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 99171d9c92..8334b9053f 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2067,6 +2067,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2090,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2609,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2636,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index d166613895..4192e7a74b 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -70,7 +70,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -978,7 +978,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1928,7 +1928,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -3233,7 +3233,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3635,6 +3635,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4040,7 +4042,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4919,7 +4921,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 928c330897..189b7cbfea 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2027,6 +2060,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2044,6 +2079,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2077,7 +2114,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2769,6 +2808,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2844,6 +2886,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2882,6 +2927,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2920,7 +2968,32 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot add infinite values with opposite signs")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot add infinite values with opposite signs")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -2999,9 +3072,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3026,7 +3097,32 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot add infinite values with opposite signs")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot add infinite values with opposite signs")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3109,15 +3205,37 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
 							   PointerGetDatum(&tspan));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
 
 Datum
 interval_um(PG_FUNCTION_ARGS)
@@ -3126,23 +3244,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3186,28 +3288,62 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot add infinite values with opposite signs")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot add infinite values with opposite signs")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3220,28 +3356,64 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot subtract infinite values with the same signs")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("cannot subtract infinite values with the same signs")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3265,6 +3437,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3325,6 +3515,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3356,6 +3551,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3377,6 +3595,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3910,6 +4133,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4365,6 +4593,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5224,6 +5458,60 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5247,6 +5535,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 21a37e21e9..333103efb1 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,27 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == PG_INT64_MIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == PG_INT64_MAX && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..2aa9b59ef2 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +268,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +865,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +877,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1578,31 +1625,31 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1728,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1816,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1827,350 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  cannot subtract infinite values with the same signs
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  cannot subtract infinite values with the same signs
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  cannot add infinite values with opposite signs
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..742095382a 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -509,13 +513,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +582,119 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
-- 
2.34.1

From 6ed93bc20db57cea2d692e9288d97b66f4a526dc Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

TODOs
1. Should we just use the months field to test for infinity?

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml             |   2 +-
 doc/src/sgml/func.sgml                 |   5 +-
 src/backend/utils/adt/date.c           |  20 ++
 src/backend/utils/adt/datetime.c       |  14 +-
 src/backend/utils/adt/timestamp.c      | 448 ++++++++++++++++++++----
 src/include/datatype/timestamp.h       |  21 ++
 src/test/regress/expected/horology.out |   6 +-
 src/test/regress/expected/interval.out | 466 +++++++++++++++++++++++--
 src/test/regress/sql/horology.sql      |   6 +-
 src/test/regress/sql/interval.sql      | 130 ++++++-
 10 files changed, 1002 insertions(+), 116 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index fdffba4442..2bcf959f70 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2316,7 +2316,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 3bf8d021c3..7ddf76da4a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9369,7 +9369,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10256,7 +10256,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 99171d9c92..8334b9053f 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2067,6 +2067,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2090,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2609,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2636,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index d166613895..4192e7a74b 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -70,7 +70,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -978,7 +978,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1928,7 +1928,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -3233,7 +3233,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3635,6 +3635,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4040,7 +4042,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4919,7 +4921,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 928c330897..d08696de97 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -79,6 +79,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(Interval *interval, char *str);
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1545,6 +1567,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2027,6 +2060,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2044,6 +2079,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2077,7 +2114,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2769,6 +2808,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2844,6 +2886,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2882,6 +2927,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2920,7 +2968,32 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -2999,9 +3072,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3026,7 +3097,32 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3109,15 +3205,37 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
 							   PointerGetDatum(&tspan));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
 
 Datum
 interval_um(PG_FUNCTION_ARGS)
@@ -3126,23 +3244,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3186,28 +3288,62 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3220,28 +3356,64 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3265,6 +3437,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3325,6 +3515,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3356,6 +3551,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3377,6 +3595,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3910,6 +4133,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4365,6 +4593,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5224,6 +5458,60 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5247,6 +5535,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 21a37e21e9..333103efb1 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,27 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == PG_INT64_MIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == PG_INT64_MAX && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..fdad2def16 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +268,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +865,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +877,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1578,31 +1625,31 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1728,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1816,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1827,350 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..742095382a 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -509,13 +513,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +582,119 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
-- 
2.34.1

From 23868228ad2c0be57408b38db76bced85ab83cb1 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] This is WIP.

TODOs
1. Should we just use the months field to test for infinity?

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  32 +
 src/backend/utils/adt/datetime.c          |  39 +-
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 695 ++++++++++++++++++----
 src/include/common/int.h                  |  18 +
 src/include/datatype/timestamp.h          |  21 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 503 ++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 149 ++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 18 files changed, 1461 insertions(+), 193 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 467b49b199..d782d23574 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2316,7 +2316,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b8dac9ef46..36b31f7163 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9393,7 +9393,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10280,7 +10280,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 99171d9c92..dc271f663c 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2067,6 +2072,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2095,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2614,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2641,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3140,6 +3165,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index d166613895..608d562b48 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -50,7 +50,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -70,7 +69,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -514,22 +513,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -620,7 +603,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -978,7 +961,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1928,7 +1911,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -2853,9 +2836,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
@@ -3233,7 +3216,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3635,6 +3618,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4040,7 +4025,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4919,7 +4904,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index a4b524ea3a..d9dca76f96 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 57de51f0db..ab80812ae5 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 928c330897..6d406d5763 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -79,6 +80,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1520,13 +1542,35 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+
+	result->time = secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -1545,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2027,6 +2082,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2044,6 +2101,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2077,7 +2136,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2208,6 +2269,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2703,43 +2787,70 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	result->time = dt1 - dt2;
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->time = dt1 - dt2;
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2769,6 +2880,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2844,6 +2958,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2882,6 +2999,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2920,7 +3040,32 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -2999,9 +3144,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3026,7 +3169,32 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3109,15 +3277,37 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
 							   PointerGetDatum(&tspan));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
 
 Datum
 interval_um(PG_FUNCTION_ARGS)
@@ -3126,23 +3316,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3186,28 +3360,62 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3220,28 +3428,64 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3265,6 +3509,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3325,6 +3587,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3356,6 +3623,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3377,6 +3667,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3664,8 +3959,37 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3784,8 +4108,37 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3910,6 +4263,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4093,6 +4451,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4365,6 +4728,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5224,6 +5593,60 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5247,6 +5670,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5516,6 +5967,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5773,6 +6231,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5839,6 +6304,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5918,6 +6388,11 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..53cc4ce4ce 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,15 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
@@ -254,6 +263,15 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 21a37e21e9..333103efb1 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,27 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i->time) == PG_INT64_MIN && (i->day) == PG_INT32_MIN && (i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i->time) == PG_INT64_MAX && (i->day) == PG_INT32_MAX && (i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index 42f802bb9d..20eb024dc8 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -112,6 +112,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -121,6 +122,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..686394c25b 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +268,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +865,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +877,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1576,33 +1623,38 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1733,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1821,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1832,382 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index edc6912e7a..d85359b28f 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2116,3 +2116,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 00379fd0fd..97230af014 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2459,6 +2459,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
 -- These tests rely on the knowledge that MSK (Europe/Moscow standard time)
@@ -3091,3 +3095,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..ed563666b0 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -507,15 +511,19 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +586,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index 1d580f77f1..e0fdfd7d74 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -393,3 +393,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 4905dd0831..598c07f064 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -454,6 +454,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
@@ -596,3 +598,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 123cdf534cc1a0e9a44e7dc8641d23e2c5b09e31 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  32 +
 src/backend/utils/adt/datetime.c          |  39 +-
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 705 ++++++++++++++++++----
 src/include/common/int.h                  |  18 +
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 563 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 174 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 18 files changed, 1516 insertions(+), 231 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 467b49b199..d782d23574 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2316,7 +2316,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b8dac9ef46..36b31f7163 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9393,7 +9393,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10280,7 +10280,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 99171d9c92..dc271f663c 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2067,6 +2072,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2095,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2614,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2641,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3140,6 +3165,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index d166613895..608d562b48 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -50,7 +50,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -70,7 +69,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -514,22 +513,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -620,7 +603,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -978,7 +961,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1928,7 +1911,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -2853,9 +2836,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
@@ -3233,7 +3216,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3635,6 +3618,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4040,7 +4025,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4919,7 +4904,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index a4b524ea3a..d9dca76f96 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 57de51f0db..ab80812ae5 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 928c330897..51438035e7 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -79,6 +80,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1520,13 +1542,35 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+
+	result->time = secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -1545,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2027,6 +2082,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2044,6 +2101,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2077,7 +2136,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2208,6 +2269,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2703,43 +2787,70 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	result->time = dt1 - dt2;
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->time = dt1 - dt2;
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2769,6 +2880,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2821,6 +2935,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2844,6 +2963,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2882,6 +3004,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2900,6 +3025,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2920,7 +3050,32 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -2999,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3026,7 +3179,32 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3109,15 +3287,37 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
 							   PointerGetDatum(&tspan));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
 
 Datum
 interval_um(PG_FUNCTION_ARGS)
@@ -3126,23 +3326,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3186,28 +3370,62 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3220,28 +3438,64 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3265,6 +3519,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3325,6 +3597,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3356,6 +3633,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3377,6 +3677,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3664,8 +3969,37 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3784,8 +4118,37 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3910,6 +4273,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4093,6 +4461,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4365,6 +4738,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5224,6 +5603,60 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5247,6 +5680,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5516,6 +5977,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5773,6 +6241,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5839,6 +6314,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5918,6 +6398,11 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..53cc4ce4ce 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,15 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
@@ -254,6 +263,15 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 21a37e21e9..fc37810c45 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -160,6 +160,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index 42f802bb9d..20eb024dc8 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -112,6 +112,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -121,6 +122,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 579e92e7b3..ecb0747323 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1576,33 +1629,38 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1681,19 +1739,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1767,7 +1827,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1776,3 +1838,382 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index edc6912e7a..d85359b28f 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2116,3 +2116,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 00379fd0fd..97230af014 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2459,6 +2459,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
 -- These tests rely on the knowledge that MSK (Europe/Moscow standard time)
@@ -3091,3 +3095,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 0517b5b82b..92c4bde930 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -507,15 +514,19 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -578,3 +589,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index 1d580f77f1..e0fdfd7d74 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -393,3 +393,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 4905dd0831..598c07f064 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -454,6 +454,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
@@ -596,3 +598,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From aaaa1b35e2b96bcf69431bbd8720523163de10cf Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 17 Dec 2022 14:21:26 -0500
Subject: [PATCH] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  32 +
 src/backend/utils/adt/datetime.c          |  39 +-
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 711 ++++++++++++++++++----
 src/include/common/int.h                  |  18 +
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 563 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 174 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 18 files changed, 1519 insertions(+), 234 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 467b49b199..d782d23574 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2316,7 +2316,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 97b3f1c1a6..c83f38d263 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9393,7 +9393,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10280,7 +10280,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 99171d9c92..dc271f663c 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2067,6 +2072,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2095,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2614,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2641,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3140,6 +3165,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 01660637a2..462df43e2e 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -50,7 +50,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -70,7 +69,7 @@ static bool DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t,
 												  const char *abbr, pg_tz *tzp,
 												  int *offset, int *isdst);
 static pg_tz *FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-								   DateTimeErrorExtra *extra);
+								   DateTimeErrorExtra * extra);
 
 
 const int	day_tab[2][13] =
@@ -514,22 +513,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -620,7 +603,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -978,7 +961,7 @@ ParseDateTime(const char *timestr, char *workbuf, size_t buflen,
 int
 DecodeDateTime(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -1928,7 +1911,7 @@ DetermineTimeZoneAbbrevOffsetInternal(pg_time_t t, const char *abbr, pg_tz *tzp,
 int
 DecodeTimeOnly(char **field, int *ftype, int nf,
 			   int *dtype, struct pg_tm *tm, fsec_t *fsec, int *tzp,
-			   DateTimeErrorExtra *extra)
+			   DateTimeErrorExtra * extra)
 {
 	int			fmask = 0,
 				tmask,
@@ -2853,9 +2836,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
@@ -3233,7 +3216,7 @@ DecodeTimezone(const char *str, int *tzp)
 int
 DecodeTimezoneAbbrev(int field, const char *lowtoken,
 					 int *ftype, int *offset, pg_tz **tz,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	const datetkn *tp;
 
@@ -3635,6 +3618,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -4032,7 +4017,7 @@ DecodeUnits(int field, const char *lowtoken, int *val)
  * separate SQLSTATE codes, so ...
  */
 void
-DateTimeParseError(int dterr, DateTimeErrorExtra *extra,
+DateTimeParseError(int dterr, DateTimeErrorExtra * extra,
 				   const char *str, const char *datatype,
 				   Node *escontext)
 {
@@ -4911,7 +4896,7 @@ InstallTimeZoneAbbrevs(TimeZoneAbbrevTable *tbl)
  */
 static pg_tz *
 FetchDynamicTimeZone(TimeZoneAbbrevTable *tbl, const datetkn *tp,
-					 DateTimeErrorExtra *extra)
+					 DateTimeErrorExtra * extra)
 {
 	DynamicZoneAbbrev *dtza;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index f3f4db5ef6..0157de73f0 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index de93db89d4..0b3b2ec94e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -79,6 +80,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -943,6 +945,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -965,8 +975,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1352,6 +1367,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1520,13 +1542,35 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+
+	result->time = secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -1545,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2032,6 +2087,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2049,6 +2106,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2082,7 +2141,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2213,6 +2274,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2708,46 +2792,73 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 	 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2777,6 +2888,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2829,6 +2943,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2852,6 +2971,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2890,6 +3012,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2908,6 +3033,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2928,7 +3058,32 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3007,9 +3162,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3034,7 +3187,32 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(timestamp)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3117,15 +3295,37 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
 							   PointerGetDatum(&tspan));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
 
 Datum
 interval_um(PG_FUNCTION_ARGS)
@@ -3134,23 +3334,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3194,28 +3378,62 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3228,28 +3446,64 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOBEGIN
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOEND
+			(span2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3273,6 +3527,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3333,6 +3605,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3364,6 +3641,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3385,6 +3685,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3672,8 +3977,37 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3792,8 +4126,37 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND
+			(dt2)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3918,6 +4281,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4101,6 +4469,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4373,6 +4746,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5232,6 +5611,60 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
+
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
  */
@@ -5255,6 +5688,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5524,6 +5985,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5781,6 +6249,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5847,6 +6322,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5926,6 +6406,11 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..53cc4ce4ce 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,15 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
@@ -254,6 +263,15 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..5caf5dcfbe 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -167,6 +167,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index de73683690..10b86963ee 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -939,6 +939,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1050,6 +1051,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1157,6 +1159,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1432,6 +1435,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1599,7 +1603,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..55d65d17d0 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1587,33 +1640,38 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1692,19 +1750,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1778,7 +1838,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1787,3 +1849,382 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 91d7c1f5cc..e6c81eb7d2 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
 -- These tests rely on the knowledge that MSK (Europe/Moscow standard time)
@@ -3100,3 +3104,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 2724a2bbc7..2494d852a6 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -173,14 +173,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -253,11 +256,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..1e1d8560bf 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -511,15 +518,19 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -582,3 +593,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index ae9ee4b56a..4545187af0 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
@@ -600,3 +602,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From ba97dfc52e7b5b967feba9008019c00977f3948e Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 12:26:28 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index be2e55bb29..64f28a85b0 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 2952414253f3a76d7b2983b9eaf57de0c5237c0e Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 12:38:58 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 24 +++++++++++++++++++-----
 src/include/common/int.h               | 13 +++++++++++++
 src/test/regress/expected/interval.out |  5 +++++
 src/test/regress/sql/interval.sql      |  4 ++++
 4 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index c266d0d02e..de80a7e5b5 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1501,13 +1501,27 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	result->time = secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..27bfb8ba9b 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,11 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..f1abf08501 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,10 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From a847277bd0ce4c8aa965685bd4a7af9ef86a6940 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  32 +
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 674 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 559 ++++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 170 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1451 insertions(+), 202 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 4df8bd1b64..df4cd287ce 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2316,7 +2316,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 15314aa3ee..4c74efc320 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9428,7 +9428,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10315,7 +10315,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index a163fbb4ab..5b4ba76eed 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2067,6 +2072,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2095,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2614,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2641,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3113,6 +3138,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 64f28a85b0..f77bf1d5eb 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..97693a68ce 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0|| INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index de80a7e5b5..b0a59425ef 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -79,6 +80,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -924,6 +926,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -946,8 +956,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1333,6 +1348,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1506,6 +1528,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
 		ereport(ERROR,
@@ -1523,6 +1546,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1540,6 +1568,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2027,6 +2066,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2044,6 +2085,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2077,7 +2120,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2208,6 +2253,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2703,46 +2771,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 	 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2772,6 +2865,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2824,6 +2920,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2847,6 +2948,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2885,6 +2989,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2903,6 +3010,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2923,7 +3035,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3002,9 +3137,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3029,7 +3162,30 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3112,15 +3268,39 @@ timestamptz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamptz_pl_interval,
 							   TimestampGetDatum(timestamp),
 							   PointerGetDatum(&tspan));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while negating an interval")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while negating an interval")));
+	}
+}
 
 Datum
 interval_um(PG_FUNCTION_ARGS)
@@ -3129,23 +3309,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3189,27 +3353,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOEND(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOBEGIN(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3223,27 +3420,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOBEGIN(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOEND(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3268,6 +3500,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3328,6 +3578,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3359,6 +3614,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3380,6 +3658,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3667,8 +3950,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3787,8 +4097,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3913,6 +4250,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4096,6 +4438,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4337,6 +4684,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -5195,6 +5548,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5219,6 +5625,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5461,6 +5895,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5691,6 +6132,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5757,6 +6205,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5836,6 +6289,11 @@ generate_series_timestamptz(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..5caf5dcfbe 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -167,6 +167,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..33842f9fbe 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1048,6 +1048,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1159,6 +1160,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1268,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,6 +1544,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1708,7 +1712,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 27bfb8ba9b..0adfe5f9fb 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1594,31 +1647,31 @@ select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.77
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1697,19 +1750,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1783,7 +1838,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1792,3 +1849,383 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+CONTEXT:  while negating an interval
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 91d7c1f5cc..e6c81eb7d2 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
 -- These tests rely on the knowledge that MSK (Europe/Moscow standard time)
@@ -3100,3 +3104,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..1d0ab322c0 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -207,14 +207,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +290,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f1abf08501..1e1d8560bf 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -517,13 +524,13 @@ select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.77
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -586,3 +593,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index ae9ee4b56a..4545187af0 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 --
 -- Test behavior with a dynamic (time-varying) timezone abbreviation.
@@ -600,3 +602,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From da22f9b3d55433c408f04056eecf0fddf60f01c9 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 12:38:58 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 24 +++++++++++++++++++-----
 src/include/common/int.h               | 13 +++++++++++++
 src/test/regress/expected/interval.out |  5 +++++
 src/test/regress/sql/interval.sql      |  4 ++++
 4 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index aaadc68ae6..b79af28ae3 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1517,13 +1517,27 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	result->time = secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..27bfb8ba9b 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,11 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..f1abf08501 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,10 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From e6edf1cf90d315918688a66374a76f48f806da94 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  32 +
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 679 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 559 ++++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 170 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1454 insertions(+), 204 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 4df8bd1b64..df4cd287ce 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2316,7 +2316,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index a3a13b895f..33fa3e6670 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index a163fbb4ab..5b4ba76eed 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2067,6 +2072,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2095,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2614,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2641,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3113,6 +3138,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 64f28a85b0..f77bf1d5eb 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index b79af28ae3..5f5b621e51 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -940,6 +942,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -962,8 +972,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1349,6 +1364,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1522,6 +1544,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
 		ereport(ERROR,
@@ -1539,6 +1562,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1556,6 +1584,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2043,6 +2082,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2060,6 +2101,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2093,7 +2136,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2224,6 +2269,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2719,46 +2787,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 	 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2788,6 +2881,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2840,6 +2936,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2863,6 +2964,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2901,6 +3005,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2919,6 +3026,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2939,7 +3051,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3018,9 +3153,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3047,7 +3180,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if TIMESTAMP_IS_NOEND(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if TIMESTAMP_IS_NOBEGIN(timestamp)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3137,9 +3293,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3190,6 +3344,33 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while negating an interval")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while negating an interval")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3197,23 +3378,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3257,27 +3422,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOEND(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOBEGIN(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3291,27 +3489,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if INTERVAL_IS_NOBEGIN(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if INTERVAL_IS_NOEND(span2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3336,6 +3569,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3396,6 +3647,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3427,6 +3683,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3448,6 +3727,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3731,8 +4015,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3851,8 +4162,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if TIMESTAMP_IS_NOBEGIN(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if TIMESTAMP_IS_NOEND(dt2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3977,6 +4315,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4160,6 +4503,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4398,6 +4746,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4742,7 +5096,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5016,7 +5370,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5256,6 +5610,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5280,6 +5687,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5522,6 +5957,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5752,6 +6194,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5818,6 +6267,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5900,6 +6354,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..5caf5dcfbe 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -167,6 +167,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..33842f9fbe 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1048,6 +1048,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1159,6 +1160,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1268,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,6 +1544,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1708,7 +1712,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 27bfb8ba9b..0adfe5f9fb 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1594,31 +1647,31 @@ select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.77
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1697,19 +1750,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1783,7 +1838,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1792,3 +1849,383 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+CONTEXT:  while negating an interval
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..1d0ab322c0 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -207,14 +207,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +290,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f1abf08501..1e1d8560bf 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -517,13 +524,13 @@ select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.77
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -586,3 +593,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 565687d49f7a5042726da1312ddbb9b1571049b9 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 12:26:28 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index be2e55bb29..64f28a85b0 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From d3543e7c410f83cbe3f3f3df9715025bc767fc5f Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  32 +
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 679 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 559 ++++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 170 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1454 insertions(+), 204 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index faf0d74104..694af4000d 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,7 +2321,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index a3a13b895f..33fa3e6670 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index a163fbb4ab..5b4ba76eed 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2067,6 +2072,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2095,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2614,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2641,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3113,6 +3138,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 64f28a85b0..f77bf1d5eb 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index b79af28ae3..c006e27dc0 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -940,6 +942,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -962,8 +972,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1349,6 +1364,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1522,6 +1544,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, 7, &result->day))
 		ereport(ERROR,
@@ -1539,6 +1562,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1556,6 +1584,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2043,6 +2082,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2060,6 +2101,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2093,7 +2136,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2224,6 +2269,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2719,46 +2787,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2788,6 +2881,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2840,6 +2936,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2863,6 +2964,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2901,6 +3005,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2919,6 +3026,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2939,7 +3051,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3018,9 +3153,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3047,7 +3180,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3137,9 +3293,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3190,6 +3344,33 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while negating an interval")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while negating an interval")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3197,23 +3378,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3257,27 +3422,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3291,27 +3489,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3336,6 +3569,24 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3396,6 +3647,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3427,6 +3683,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3448,6 +3727,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3731,8 +4015,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3851,8 +4162,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3977,6 +4315,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4160,6 +4503,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4398,6 +4746,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4742,7 +5096,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5016,7 +5370,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5256,6 +5610,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5280,6 +5687,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5522,6 +5957,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5752,6 +6194,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5818,6 +6267,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5900,6 +6354,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..5caf5dcfbe 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -167,6 +167,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..33842f9fbe 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1048,6 +1048,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1159,6 +1160,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1268,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,6 +1544,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1708,7 +1712,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 27bfb8ba9b..0adfe5f9fb 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1594,31 +1647,31 @@ select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.77
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1697,19 +1750,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1783,7 +1838,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1792,3 +1849,383 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+CONTEXT:  while negating an interval
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..1d0ab322c0 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -207,14 +207,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +290,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f1abf08501..1e1d8560bf 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -517,13 +524,13 @@ select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.77
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -586,3 +593,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 41fa5de65c757d72331aff6bb626fab76390e9db Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 12:26:28 -0400
Subject: [PATCH 1/2] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index be2e55bb29..64f28a85b0 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 242ffd232bef606c9c948f0ee9980152fb9e3bec Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 12:38:58 -0400
Subject: [PATCH 2/2] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 24 +++++++++++++++++++-----
 src/include/common/int.h               | 13 +++++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  5 +++++
 src/test/regress/sql/interval.sql      |  4 ++++
 5 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index aaadc68ae6..ccf0019a3c 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1517,13 +1517,27 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	result->time = secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..27bfb8ba9b 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,11 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..f1abf08501 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,10 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

commit e345924db6e6b531f98124159731560a38eae7d0
Author: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date:   Fri Mar 31 15:41:25 2023 +0530

    fixup! Add infinite interval values

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index c006e27dc0..79842d3e0d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3566,6 +3566,7 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
@@ -3574,6 +3575,15 @@ interval_mul(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (is_factor_inf != 0)
+	{
+		if (is_factor_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	/*
 	 * Multiplying infinite interval by finite number keeps it infinite but
 	 * may change the sign.

commit 29d8501bb0e1b727abc81e862185770fd8e3a6c9
Author: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date:   Fri Mar 31 18:02:25 2023 +0530

    fixup! Add infinite interval values

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index c006e27dc0..cd05c61de3 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3566,6 +3566,7 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
@@ -3580,12 +3581,35 @@ interval_mul(PG_FUNCTION_ARGS)
 	 */
 	if (INTERVAL_NOT_FINITE(span))
 	{
-		if (factor < 0.0)
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
 			interval_um_internal(span, result);
 		else
 			memcpy(result, span, sizeof(Interval));
 		PG_RETURN_INTERVAL_P(result);
 	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
 
 	result_double = span->month * factor;
 	if (isnan(result_double) ||

From 765aa1ebf9de5e5d48e1c588f7bde70074374979 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index aaadc68ae6..5c25e12795 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1517,13 +1517,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From f6bf9c201a94a0b338dff520442ac5e8d2922c89 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index be2e55bb29..64f28a85b0 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 4947a39a755a93ddd3fd5c19610f91594af4ee5a Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  35 +
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 821 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 606 ++++++++++++++--
 src/test/regress/expected/timestamp.out   |  67 ++
 src/test/regress/expected/timestamptz.out |  67 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 170 ++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1629 insertions(+), 231 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index f6b867f344..2b454e7fbc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,7 +2321,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 918a492234..13f7033572 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index a163fbb4ab..cea2590ba9 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,12 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range"),
+				 errcontext("while converting interval to time")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2054,6 +2060,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2067,6 +2075,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2098,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2617,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2644,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3113,6 +3141,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 64f28a85b0..f77bf1d5eb 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 5c25e12795..78133dfb17 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -940,6 +942,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -962,8 +972,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1349,6 +1364,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1514,34 +1536,47 @@ make_interval(PG_FUNCTION_ARGS)
 	if (isinf(secs) || isnan(secs))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while making an interval")));
 
 	result = (Interval *) palloc(sizeof(Interval));
 	result->month = months;
 	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while making an interval")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while making an interval")));
 
 	secs = rint(float8_mul(secs, USECS_PER_SEC));
 	if (!FLOAT8_FITS_IN_INT64(secs))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while making an interval")));
 	result->time = (int64) secs;
 	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while making an interval")));
 	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while making an interval")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while making an interval")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -1560,6 +1595,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2047,6 +2093,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2064,6 +2112,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2097,7 +2147,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2228,6 +2280,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2723,46 +2798,74 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range"),
+					 errcontext("while subtracting timestamps")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range"),
+					 errcontext("while subtracting timestamps")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while subtracting timestamps")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2792,6 +2895,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2801,7 +2907,8 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("interval out of range"),
+					 errcontext("while justifying an interval")));
 	}
 
 	/*
@@ -2818,7 +2925,8 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while justifying an interval")));
 
 	if (result->month > 0 &&
 		(result->day < 0 || (result->day == 0 && result->time < 0)))
@@ -2844,6 +2952,12 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while justifying an interval")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2867,11 +2981,15 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while justifying an interval hours")));
 
 	if (result->day > 0 && result->time < 0)
 	{
@@ -2884,6 +3002,12 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while justifying an interval hours")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2905,12 +3029,16 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while justifying an interval days")));
 
 	if (result->month > 0 && result->day < 0)
 	{
@@ -2923,6 +3051,12 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while justifying an interval days")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2943,7 +3077,32 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding an interval and timestamp")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding an interval and timestamp")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -2956,7 +3115,8 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 			if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamp")));
 
 			tm->tm_mon += span->month;
 			if (tm->tm_mon > MONTHS_PER_YEAR)
@@ -2977,7 +3137,8 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 			if (tm2timestamp(tm, fsec, NULL, &timestamp) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamp")));
 		}
 
 		if (span->day != 0)
@@ -2990,7 +3151,8 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 			if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamp")));
 
 			/* Add days by converting to and from Julian */
 			julian = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) + span->day;
@@ -2999,7 +3161,8 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 			if (tm2timestamp(tm, fsec, NULL, &timestamp) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamp")));
 		}
 
 		timestamp += span->time;
@@ -3007,7 +3170,8 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 		if (!IS_VALID_TIMESTAMP(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("timestamp out of range"),
+					 errcontext("while adding an interval and timestamp")));
 
 		result = timestamp;
 	}
@@ -3022,9 +3186,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3051,7 +3213,32 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding an interval and timestamptz")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding an interval and timestamptz")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3068,7 +3255,8 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 			if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, attimezone) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamptz")));
 
 			tm->tm_mon += span->month;
 			if (tm->tm_mon > MONTHS_PER_YEAR)
@@ -3091,7 +3279,8 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 			if (tm2timestamp(tm, fsec, &tz, &timestamp) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamptz")));
 		}
 
 		if (span->day != 0)
@@ -3104,7 +3293,8 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 			if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, attimezone) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamptz")));
 
 			/* Add days by converting to and from Julian */
 			julian = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) + span->day;
@@ -3115,7 +3305,8 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 			if (tm2timestamp(tm, fsec, &tz, &timestamp) != 0)
 				ereport(ERROR,
 						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-						 errmsg("timestamp out of range")));
+						 errmsg("timestamp out of range"),
+						 errcontext("while adding an interval and timestamptz")));
 		}
 
 		timestamp += span->time;
@@ -3123,7 +3314,8 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 		if (!IS_VALID_TIMESTAMP(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("timestamp out of range"),
+					 errcontext("while adding an interval and timestamptz")));
 
 		result = timestamp;
 	}
@@ -3141,9 +3333,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3194,6 +3384,33 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while negating an interval")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while negating an interval")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3201,23 +3418,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3261,27 +3462,66 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding intervals")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding intervals")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding intervals")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding intervals")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding intervals")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while adding intervals")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3295,27 +3535,68 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while subtracting intervals")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while subtracting intervals")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while subtracting intervals")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while subtracting intervals")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while subtracting intervals")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while subtracting intervals")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3337,15 +3618,59 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while multiplying an interval and float8")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while multiplying an interval and float8")));
 	result->month = (int32) result_double;
 
 	result_double = span->day * factor;
@@ -3353,7 +3678,8 @@ interval_mul(PG_FUNCTION_ARGS)
 		result_double > INT_MAX || result_double < INT_MIN)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while multiplying an interval and float8")));
 	result->day = (int32) result_double;
 
 	/*
@@ -3397,9 +3723,16 @@ interval_mul(PG_FUNCTION_ARGS)
 	if (isnan(result_double) || !FLOAT8_FITS_IN_INT64(result_double))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+				 errmsg("interval out of range"),
+				 errcontext("while multiplying an interval and float8")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while multiplying an interval and float8")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3431,6 +3764,31 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while dividing an interval by float8")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range"),
+					 errcontext("while dividing an interval by float8")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3452,6 +3810,12 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range"),
+				 errcontext("while dividing an interval by float8")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3735,8 +4099,37 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range"),
+					 errcontext("while executing timestamp_age")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range"),
+					 errcontext("while executing timestamp_age")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3819,12 +4212,14 @@ timestamp_age(PG_FUNCTION_ARGS)
 		if (itm2interval(tm, result) != 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("interval out of range"),
+					 errcontext("while executing timestamp_age")));
 	}
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("timestamp out of range")));
+				 errmsg("timestamp out of range"),
+				 errcontext("while executing timestamp_age")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3855,8 +4250,37 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range"),
+					 errcontext("while executing timestamptz_age")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range"),
+					 errcontext("while executing timestamptz_age")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3943,12 +4367,14 @@ timestamptz_age(PG_FUNCTION_ARGS)
 		if (itm2interval(tm, result) != 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("interval out of range"),
+					 errcontext("while executing timestamptz_age")));
 	}
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("timestamp out of range")));
+				 errmsg("timestamp out of range"),
+				 errcontext("while executing timestamptz_age")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3981,6 +4407,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4164,6 +4595,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4402,6 +4838,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4746,7 +5188,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5020,7 +5462,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5260,6 +5702,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5284,6 +5779,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5526,6 +6049,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5756,6 +6286,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5822,6 +6359,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5904,6 +6446,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..33842f9fbe 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1048,6 +1048,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1159,6 +1160,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1268,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,6 +1544,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1708,7 +1712,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..3610755fa9 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -266,22 +309,23 @@ LINE 1: INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483648 years'...
 -- Test edge-case overflow detection in interval multiplication
 select extract(epoch from '256 microseconds'::interval * (2^55)::float8);
 ERROR:  interval out of range
+CONTEXT:  while multiplying an interval and float8
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL_OF r1, INTERVAL_TBL_OF r2
    WHERE r1.f1 > r2.f1
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +340,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +430,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,8 +475,13 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+CONTEXT:  while justifying an interval hours
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+CONTEXT:  while justifying an interval days
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
+CONTEXT:  while justifying an interval days
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
   1 month -1 hour   
@@ -450,26 +501,36 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+CONTEXT:  while justifying an interval
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+CONTEXT:  while justifying an interval
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+CONTEXT:  while justifying an interval
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+CONTEXT:  while justifying an interval
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+CONTEXT:  while justifying an interval
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
+CONTEXT:  while justifying an interval
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
 SET IntervalStyle TO postgres;
@@ -820,8 +881,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +893,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1590,37 +1653,40 @@ LINE 1: select interval '-2147483648 months -2147483648 days -922337...
 -- overflowing using make_interval
 select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
 ERROR:  interval out of range
+CONTEXT:  while making an interval
 select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
 ERROR:  interval out of range
+CONTEXT:  while making an interval
 SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
+CONTEXT:  while making an interval
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1673,8 +1739,10 @@ select make_interval(months := 'NaN'::float::int);
 ERROR:  integer out of range
 select make_interval(secs := 'inf');
 ERROR:  interval out of range
+CONTEXT:  while making an interval
 select make_interval(secs := 'NaN');
 ERROR:  interval out of range
+CONTEXT:  while making an interval
 select make_interval(secs := 7e12);
            make_interval            
 ------------------------------------
@@ -1699,19 +1767,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1855,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1866,415 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding intervals
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding intervals
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+CONTEXT:  while adding intervals
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+CONTEXT:  while adding intervals
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while subtracting intervals
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while subtracting intervals
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+CONTEXT:  while subtracting intervals
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+CONTEXT:  while subtracting intervals
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamp
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamptz
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamptz
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamptz
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while adding an interval and timestamptz
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+CONTEXT:  while negating an interval
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+CONTEXT:  while multiplying an interval and float8
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+CONTEXT:  while multiplying an interval and float8
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+CONTEXT:  while multiplying an interval and float8
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while dividing an interval by float8
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while dividing an interval by float8
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+CONTEXT:  while dividing an interval by float8
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+CONTEXT:  while dividing an interval by float8
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+CONTEXT:  while dividing an interval by float8
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+CONTEXT:  while dividing an interval by float8
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+CONTEXT:  while dividing an interval by float8
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+CONTEXT:  while converting interval to time
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+CONTEXT:  while converting interval to time
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..b586f30ba1 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -1216,6 +1216,7 @@ SELECT timestamp '294276-12-31 23:59:59' - timestamp '1999-12-23 19:59:04.224193
 
 SELECT timestamp '294276-12-31 23:59:59' - timestamp '1999-12-23 19:59:04.224192' AS overflows;
 ERROR:  interval out of range
+CONTEXT:  while subtracting timestamps
 -- TO_CHAR()
 SELECT to_char(d1, 'DAY Day day DY Dy dy MONTH Month month RM MON Mon mon')
    FROM TIMESTAMP_TBL;
@@ -2125,3 +2126,69 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+CONTEXT:  while subtracting timestamps
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+CONTEXT:  while subtracting timestamps
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+CONTEXT:  while executing timestamp_age
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
+CONTEXT:  while executing timestamp_age
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..c532c96958 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -1340,6 +1340,7 @@ SELECT timestamptz '294276-12-31 23:59:59 UTC' - timestamptz '1999-12-23 19:59:0
 
 SELECT timestamptz '294276-12-31 23:59:59 UTC' - timestamptz '1999-12-23 19:59:04.224192 UTC' AS overflows;
 ERROR:  interval out of range
+CONTEXT:  while subtracting timestamps
 -- TO_CHAR()
 SELECT to_char(d1, 'DAY Day day DY Dy dy MONTH Month month RM MON Mon mon')
    FROM TIMESTAMPTZ_TBL;
@@ -2468,6 +2469,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3159,65 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+CONTEXT:  while subtracting timestamps
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+CONTEXT:  while subtracting timestamps
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+CONTEXT:  while executing timestamptz_age
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
+CONTEXT:  while executing timestamptz_age
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..1d0ab322c0 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -207,14 +207,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +290,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..dab0e07999 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From e50d4ca6321c58d216d563f74502356d721c2b4b Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sun, 2 Apr 2023 17:15:01 -0400
Subject: [PATCH 4/4] Clean up infinity arithmetic

---
 src/backend/utils/adt/timestamp.c         | 254 +++++++---------------
 src/test/regress/expected/interval.out    |  16 +-
 src/test/regress/expected/timestamp.out   |   4 +-
 src/test/regress/expected/timestamptz.out |   4 +-
 4 files changed, 86 insertions(+), 192 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 78133dfb17..50a47f3778 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -2788,16 +2788,15 @@ timestamp_larger(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(result);
 }
 
-
-Datum
-timestamp_mi(PG_FUNCTION_ARGS)
+/* Helper function to perform subtraction between two potentially infinite
+ * timestamps.
+ *
+ * Returns true if either dt1 or dt1 were infinite and result was set,
+ * false otherwise.
+ */
+bool
+infinite_timestamp_mi_internal(Timestamp dt1, Timestamp dt2, Interval *result)
 {
-	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
-	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);
-	Interval   *result;
-
-	result = (Interval *) palloc(sizeof(Interval));
-
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
@@ -2812,6 +2811,7 @@ timestamp_mi(PG_FUNCTION_ARGS)
 					 errcontext("while subtracting timestamps")));
 		else
 			INTERVAL_NOBEGIN(result);
+		return true;
 	}
 	else if (TIMESTAMP_IS_NOEND(dt1))
 	{
@@ -2822,11 +2822,34 @@ timestamp_mi(PG_FUNCTION_ARGS)
 					 errcontext("while subtracting timestamps")));
 		else
 			INTERVAL_NOEND(result);
+		return true;
 	}
 	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+	{
 		INTERVAL_NOEND(result);
+		return true;
+	}
 	else if (TIMESTAMP_IS_NOEND(dt2))
+	{
 		INTERVAL_NOBEGIN(result);
+		return true;
+	}
+	else
+		return false;
+}
+
+Datum
+timestamp_mi(PG_FUNCTION_ARGS)
+{
+	Timestamp	dt1 = PG_GETARG_TIMESTAMP(0);
+	Timestamp	dt2 = PG_GETARG_TIMESTAMP(1);
+	Interval   *result;
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (infinite_timestamp_mi_internal(dt1, dt2, result))
+	{
+	}
 	else
 	{
 		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
@@ -3060,23 +3083,15 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	PG_RETURN_INTERVAL_P(result);
 }
 
-/* timestamp_pl_interval()
- * Add an interval to a timestamp data type.
- * Note that interval has provisions for qualitative year/month and day
- *	units, so try to do the right thing with them.
- * To add a month, increment the month, and use the same day of month.
- * Then, if the next month has fewer days, set the day of month
- *	to the last day of month.
- * To add a day, increment the mday, and use the same time of day.
- * Lastly, add in the "quantitative time".
+/* Helper function to perform addition between a potentially infinite
+ * timestamp and a potentially infinite interval.
+ *
+ * Returns true if either dt1 or dt1 were infinite and result was set,
+ * false otherwise.
  */
-Datum
-timestamp_pl_interval(PG_FUNCTION_ARGS)
+bool
+infinite_timestamp_pl_interval_internal(Timestamp timestamp, Interval *span, Timestamp *result)
 {
-	Timestamp	timestamp = PG_GETARG_TIMESTAMP(0);
-	Interval   *span = PG_GETARG_INTERVAL_P(1);
-	Timestamp	result;
-
 	/*
 	 * Adding two infinites with the same sign results in an infinite
 	 * timestamp with the same sign. Adding two infintes with different signs
@@ -3090,7 +3105,8 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 					 errmsg("interval out of range"),
 					 errcontext("while adding an interval and timestamp")));
 		else
-			TIMESTAMP_NOBEGIN(result);
+			TIMESTAMP_NOBEGIN(*result);
+		return true;
 	}
 	else if (INTERVAL_IS_NOEND(span))
 	{
@@ -3100,11 +3116,36 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 					 errmsg("interval out of range"),
 					 errcontext("while adding an interval and timestamp")));
 		else
-			TIMESTAMP_NOEND(result);
+			TIMESTAMP_NOEND(*result);
+		return true;
 	}
 	else if (TIMESTAMP_NOT_FINITE(timestamp))
-		result = timestamp;
+	{
+		*result = timestamp;
+		return true;
+	}
 	else
+		return false;
+}
+
+/* timestamp_pl_interval()
+ * Add an interval to a timestamp data type.
+ * Note that interval has provisions for qualitative year/month and day
+ *	units, so try to do the right thing with them.
+ * To add a month, increment the month, and use the same day of month.
+ * Then, if the next month has fewer days, set the day of month
+ *	to the last day of month.
+ * To add a day, increment the mday, and use the same time of day.
+ * Lastly, add in the "quantitative time".
+ */
+Datum
+timestamp_pl_interval(PG_FUNCTION_ARGS)
+{
+	Timestamp	timestamp = PG_GETARG_TIMESTAMP(0);
+	Interval   *span = PG_GETARG_INTERVAL_P(1);
+	Timestamp	result;
+
+	if (!infinite_timestamp_pl_interval_internal(timestamp, span, &result))
 	{
 		if (span->month != 0)
 		{
@@ -3193,7 +3234,6 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 							   PointerGetDatum(&tspan));
 }
 
-
 /* timestamptz_pl_interval_internal()
  * Add an interval to a timestamptz, in the given (or session) timezone.
  *
@@ -3213,34 +3253,7 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	/*
-	 * Adding two infinites with the same sign results in an infinite
-	 * timestamp with the same sign. Adding two infintes with different signs
-	 * results in an error.
-	 */
-	if (INTERVAL_IS_NOBEGIN(span))
-	{
-		if (TIMESTAMP_IS_NOEND(timestamp))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while adding an interval and timestamptz")));
-		else
-			TIMESTAMP_NOBEGIN(result);
-	}
-	else if (INTERVAL_IS_NOEND(span))
-	{
-		if (TIMESTAMP_IS_NOBEGIN(timestamp))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while adding an interval and timestamptz")));
-		else
-			TIMESTAMP_NOEND(result);
-	}
-	else if (TIMESTAMP_NOT_FINITE(timestamp))
-		result = timestamp;
-	else
+	if (!infinite_timestamp_pl_interval_internal(timestamp, span, &result))
 	{
 		/* Use session timezone if caller asks for default */
 		if (attimezone == NULL)
@@ -3529,76 +3542,9 @@ interval_pl(PG_FUNCTION_ARGS)
 Datum
 interval_mi(PG_FUNCTION_ARGS)
 {
-	Interval   *span1 = PG_GETARG_INTERVAL_P(0);
-	Interval   *span2 = PG_GETARG_INTERVAL_P(1);
-	Interval   *result;
-
-	result = (Interval *) palloc(sizeof(Interval));
-
-	/*
-	 * Subtracting two infinite intervals with different signs results in an
-	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte intervals with the same sign results in an error.
-	 */
-	if (INTERVAL_IS_NOBEGIN(span1))
-	{
-		if (INTERVAL_IS_NOBEGIN(span2))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while subtracting intervals")));
-		else
-			INTERVAL_NOBEGIN(result);
-	}
-	else if (INTERVAL_IS_NOEND(span1))
-	{
-		if (INTERVAL_IS_NOEND(span2))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while subtracting intervals")));
-		else
-			INTERVAL_NOEND(result);
-	}
-	else if (INTERVAL_IS_NOBEGIN(span2))
-		INTERVAL_NOEND(result);
-	else if (INTERVAL_IS_NOEND(span2))
-		INTERVAL_NOBEGIN(result);
-	else
-	{
-		result->month = span1->month - span2->month;
-		/* overflow check copied from int4mi */
-		if (!SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while subtracting intervals")));
-
-		result->day = span1->day - span2->day;
-		if (!SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while subtracting intervals")));
-
-		result->time = span1->time - span2->time;
-		if (!SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while subtracting intervals")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range"),
-					 errcontext("while subtracting intervals")));
-	}
-
-	PG_RETURN_INTERVAL_P(result);
+	return DirectFunctionCall2(interval_pl,
+							   PG_GETARG_INTERVAL_P(0),
+							   DirectFunctionCall1(interval_um, PG_GETARG_INTERVAL_P(1)));
 }
 
 /*
@@ -4099,35 +4045,9 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	/*
-	 * Subtracting two infinite timestamps with different signs results in an
-	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
-	 */
-	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	if (infinite_timestamp_mi_internal(dt1, dt2, result))
 	{
-		if (TIMESTAMP_IS_NOBEGIN(dt2))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range"),
-					 errcontext("while executing timestamp_age")));
-		else
-			INTERVAL_NOBEGIN(result);
 	}
-	else if (TIMESTAMP_IS_NOEND(dt1))
-	{
-		if (TIMESTAMP_IS_NOEND(dt2))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range"),
-					 errcontext("while executing timestamp_age")));
-		else
-			INTERVAL_NOEND(result);
-	}
-	else if (TIMESTAMP_IS_NOBEGIN(dt2))
-		INTERVAL_NOEND(result);
-	else if (TIMESTAMP_IS_NOEND(dt2))
-		INTERVAL_NOBEGIN(result);
 	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
 			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
@@ -4250,35 +4170,9 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	/*
-	 * Subtracting two infinite timestamps with different signs results in an
-	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
-	 */
-	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	if (infinite_timestamp_mi_internal(dt1, dt2, result))
 	{
-		if (TIMESTAMP_IS_NOBEGIN(dt2))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range"),
-					 errcontext("while executing timestamptz_age")));
-		else
-			INTERVAL_NOBEGIN(result);
 	}
-	else if (TIMESTAMP_IS_NOEND(dt1))
-	{
-		if (TIMESTAMP_IS_NOEND(dt2))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range"),
-					 errcontext("while executing timestamptz_age")));
-		else
-			INTERVAL_NOEND(result);
-	}
-	else if (TIMESTAMP_IS_NOBEGIN(dt2))
-		INTERVAL_NOEND(result);
-	else if (TIMESTAMP_IS_NOEND(dt2))
-		INTERVAL_NOBEGIN(result);
 	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
 			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 3610755fa9..9cf23e2bbb 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1983,7 +1983,7 @@ ERROR:  interval out of range
 CONTEXT:  while adding intervals
 SELECT interval 'infinity' - interval 'infinity';
 ERROR:  interval out of range
-CONTEXT:  while subtracting intervals
+CONTEXT:  while adding intervals
 SELECT interval 'infinity' - interval '-infinity';
  ?column? 
 ----------
@@ -1998,7 +1998,7 @@ SELECT interval '-infinity' - interval 'infinity';
 
 SELECT interval '-infinity' - interval '-infinity';
 ERROR:  interval out of range
-CONTEXT:  while subtracting intervals
+CONTEXT:  while adding intervals
 SELECT interval 'infinity' - interval '10 days';
  ?column? 
 ----------
@@ -2013,10 +2013,10 @@ SELECT interval '-infinity' - interval '10 days';
 
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
 ERROR:  interval out of range
-CONTEXT:  while subtracting intervals
+CONTEXT:  while adding intervals
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
 ERROR:  interval out of range
-CONTEXT:  while subtracting intervals
+CONTEXT:  while adding intervals
 SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
  ?column? 
 ----------
@@ -2109,10 +2109,10 @@ SELECT timestamptz 'infinity' + interval 'infinity';
 
 SELECT timestamptz 'infinity' + interval '-infinity';
 ERROR:  interval out of range
-CONTEXT:  while adding an interval and timestamptz
+CONTEXT:  while adding an interval and timestamp
 SELECT timestamptz '-infinity' + interval 'infinity';
 ERROR:  interval out of range
-CONTEXT:  while adding an interval and timestamptz
+CONTEXT:  while adding an interval and timestamp
 SELECT timestamptz '-infinity' + interval '-infinity';
  ?column?  
 -----------
@@ -2121,7 +2121,7 @@ SELECT timestamptz '-infinity' + interval '-infinity';
 
 SELECT timestamptz 'infinity' - interval 'infinity';
 ERROR:  interval out of range
-CONTEXT:  while adding an interval and timestamptz
+CONTEXT:  while adding an interval and timestamp
 SELECT timestamptz 'infinity' - interval '-infinity';
  ?column? 
 ----------
@@ -2136,7 +2136,7 @@ SELECT timestamptz '-infinity' - interval 'infinity';
 
 SELECT timestamptz '-infinity' - interval '-infinity';
 ERROR:  interval out of range
-CONTEXT:  while adding an interval and timestamptz
+CONTEXT:  while adding an interval and timestamp
 SELECT time '11:27:42' + interval 'infinity';
 ERROR:  cannot add infinite interval to time
 SELECT time '11:27:42' + interval '-infinity';
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index b586f30ba1..470c2bf52c 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2176,7 +2176,7 @@ select age(timestamp '-infinity');
 
 select age(timestamp 'infinity', timestamp 'infinity');
 ERROR:  timestamp out of range
-CONTEXT:  while executing timestamp_age
+CONTEXT:  while subtracting timestamps
 select age(timestamp 'infinity', timestamp '-infinity');
    age    
 ----------
@@ -2191,4 +2191,4 @@ select age(timestamp '-infinity', timestamp 'infinity');
 
 select age(timestamp '-infinity', timestamp '-infinity');
 ERROR:  timestamp out of range
-CONTEXT:  while executing timestamp_age
+CONTEXT:  while subtracting timestamps
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index c532c96958..e98359872e 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -3205,7 +3205,7 @@ SELECT age(timestamptz '-infinity');
 
 SELECT age(timestamptz 'infinity', timestamptz 'infinity');
 ERROR:  timestamp out of range
-CONTEXT:  while executing timestamptz_age
+CONTEXT:  while subtracting timestamps
 SELECT age(timestamptz 'infinity', timestamptz '-infinity');
    age    
 ----------
@@ -3220,4 +3220,4 @@ SELECT age(timestamptz '-infinity', timestamptz 'infinity');
 
 SELECT age(timestamptz '-infinity', timestamptz '-infinity');
 ERROR:  timestamp out of range
-CONTEXT:  while executing timestamptz_age
+CONTEXT:  while subtracting timestamps
-- 
2.34.1

From f6bf9c201a94a0b338dff520442ac5e8d2922c89 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index be2e55bb29..64f28a85b0 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 765aa1ebf9de5e5d48e1c588f7bde70074374979 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index aaadc68ae6..5c25e12795 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1517,13 +1517,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From b0cf51ee8824bb531f8b90e087dbcbab1c507de7 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 706 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   6 +-
 src/test/regress/expected/interval.out    | 558 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   6 +-
 src/test/regress/sql/interval.sql         | 170 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1482 insertions(+), 204 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index f6b867f344..2b454e7fbc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,7 +2321,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 918a492234..13f7033572 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index a163fbb4ab..77931a567f 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2054,6 +2059,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2067,6 +2074,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2097,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2616,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2643,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3113,6 +3140,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 64f28a85b0..f77bf1d5eb 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 5c25e12795..43853d11ca 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -940,6 +942,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -962,8 +972,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1349,6 +1364,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1522,6 +1544,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1543,6 +1566,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1560,6 +1588,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2047,6 +2086,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2064,6 +2105,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2097,7 +2140,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2228,6 +2273,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2723,46 +2791,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2792,6 +2885,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2844,6 +2940,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2867,6 +2968,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2884,6 +2988,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2905,6 +3014,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2923,6 +3035,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2943,7 +3060,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3022,9 +3162,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3051,7 +3189,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3141,9 +3302,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3194,6 +3353,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3201,23 +3385,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3261,27 +3429,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3295,27 +3496,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3337,9 +3573,51 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3400,6 +3678,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3431,6 +3714,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3452,6 +3758,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3735,8 +4046,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3855,8 +4193,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3981,6 +4346,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4164,6 +4534,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4402,6 +4777,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4746,7 +5127,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5020,7 +5401,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5260,6 +5641,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5284,6 +5718,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5526,6 +5988,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5756,6 +6225,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5822,6 +6298,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5904,6 +6385,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..33842f9fbe 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1048,6 +1048,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
              t              |     i     |            add             |          subtract          
 ----------------------------+-----------+----------------------------+----------------------------
@@ -1159,6 +1160,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1268,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,6 +1544,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1708,7 +1712,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..48a29f8c6a 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,382 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..1d0ab322c0 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -207,14 +207,17 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
   FROM TIMESTAMP_TBL t, INTERVAL_TBL i
   WHERE t.d1 BETWEEN '1990-01-01' AND '2001-01-01'
     AND i.f1 BETWEEN '00:00' AND '23:00'
+    AND isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +290,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..dab0e07999 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,134 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 0adfe5f9fb..ebb4208ad7 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2161,6 +2161,26 @@ SELECT interval '-infinity' * 'nan';
 ERROR:  interval out of range
 SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
 ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
 SELECT interval 'infinity' / 'infinity';
 ERROR:  interval out of range
 SELECT interval 'infinity' / '-infinity';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 1e1d8560bf..549ceb57c1 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -690,6 +690,12 @@ SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
 SELECT interval 'infinity' * 'nan';
 SELECT interval '-infinity' * 'nan';
 SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
 
 SELECT interval 'infinity' / 'infinity';
 SELECT interval 'infinity' / '-infinity';

From f6bf9c201a94a0b338dff520442ac5e8d2922c89 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index be2e55bb29..64f28a85b0 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 34c3589f1010b978ac15d78fc8bd684e157803f5 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 706 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |   5 +-
 src/test/regress/expected/interval.out    | 578 ++++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 176 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1506 insertions(+), 204 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index f6b867f344..2b454e7fbc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,7 +2321,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 918a492234..13f7033572 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index a163fbb4ab..77931a567f 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2054,6 +2059,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2067,6 +2074,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2097,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2616,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2643,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3113,6 +3140,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 64f28a85b0..f77bf1d5eb 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 5c25e12795..43853d11ca 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -940,6 +942,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -962,8 +972,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1349,6 +1364,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1522,6 +1544,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1543,6 +1566,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1560,6 +1588,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2047,6 +2086,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2064,6 +2105,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2097,7 +2140,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2228,6 +2273,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2723,46 +2791,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2792,6 +2885,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2844,6 +2940,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2867,6 +2968,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2884,6 +2988,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2905,6 +3014,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2923,6 +3035,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2943,7 +3060,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3022,9 +3162,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3051,7 +3189,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3141,9 +3302,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3194,6 +3353,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3201,23 +3385,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3261,27 +3429,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3295,27 +3496,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3337,9 +3573,51 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3400,6 +3678,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3431,6 +3714,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3452,6 +3758,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3735,8 +4046,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3855,8 +4193,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3981,6 +4346,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4164,6 +4534,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4402,6 +4777,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4746,7 +5127,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5020,7 +5401,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5260,6 +5641,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5284,6 +5718,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5526,6 +5988,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5756,6 +6225,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5822,6 +6298,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5904,6 +6385,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..d54a8eb801 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,6 +1543,7 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
@@ -1708,7 +1711,7 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..25ec3ac2e2 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,402 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..8417238aae 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..f24609532f 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,140 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamp '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 765aa1ebf9de5e5d48e1c588f7bde70074374979 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index aaadc68ae6..5c25e12795 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1517,13 +1517,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From f6bf9c201a94a0b338dff520442ac5e8d2922c89 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index be2e55bb29..64f28a85b0 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From d166531ece4668e9f56ab2deedf5ab27513950c2 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 706 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1544 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index f6b867f344..2b454e7fbc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,7 +2321,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 918a492234..13f7033572 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index a163fbb4ab..77931a567f 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2023,6 +2023,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2054,6 +2059,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2067,6 +2074,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2085,6 +2097,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2599,6 +2616,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2621,6 +2643,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3113,6 +3140,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 64f28a85b0..f77bf1d5eb 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fe37e65af0..e2cc6049f2 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 5c25e12795..43853d11ca 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -940,6 +942,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -962,8 +972,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1349,6 +1364,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1522,6 +1544,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1543,6 +1566,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1560,6 +1588,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2047,6 +2086,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2064,6 +2105,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2097,7 +2140,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2228,6 +2273,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2723,46 +2791,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2792,6 +2885,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2844,6 +2940,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2867,6 +2968,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2884,6 +2988,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2905,6 +3014,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2923,6 +3035,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2943,7 +3060,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3022,9 +3162,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3051,7 +3189,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3141,9 +3302,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3194,6 +3353,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3201,23 +3385,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3261,27 +3429,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3295,27 +3496,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3337,9 +3573,51 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3400,6 +3678,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3431,6 +3714,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3452,6 +3758,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3735,8 +4046,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3855,8 +4193,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3981,6 +4346,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4164,6 +4534,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4402,6 +4777,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4746,7 +5127,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5020,7 +5401,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5260,6 +5641,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5284,6 +5718,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5526,6 +5988,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5756,6 +6225,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5822,6 +6298,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5904,6 +6385,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index edd59dc432..bcb54a7238 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -114,6 +114,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -123,6 +124,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..4bbbab6431 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,378 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..26e8c131fd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,136 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 765aa1ebf9de5e5d48e1c588f7bde70074374979 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index aaadc68ae6..5c25e12795 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1517,13 +1517,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From acef69449a1c8f81f6b69f580585bf6923e84d51 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From 9472024ef0de1056e91c559277fc0deedd7a79e8 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5d8d583ddc..dc79cbb4db 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From 779987d14fd71bb8b87c720f78ed4b042d5e9b50 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 706 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1544 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..507f3cb1cc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8303aad35f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..e854a8cd1e 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index dc79cbb4db..c39fd37b7f 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..1223a9775d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3329,9 +3565,51 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3670,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3706,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3750,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4038,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4185,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4338,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4526,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4769,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5119,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5393,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5633,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5710,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5980,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6217,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6290,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6377,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..4bbbab6431 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,378 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..26e8c131fd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,136 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From 9472024ef0de1056e91c559277fc0deedd7a79e8 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5d8d583ddc..dc79cbb4db 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From acef69449a1c8f81f6b69f580585bf6923e84d51 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From 779987d14fd71bb8b87c720f78ed4b042d5e9b50 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 706 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1544 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..507f3cb1cc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8303aad35f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..e854a8cd1e 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index dc79cbb4db..c39fd37b7f 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..1223a9775d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3329,9 +3565,51 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3670,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3706,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3750,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4038,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4185,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4338,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4526,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4769,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5119,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5393,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5633,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5710,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5980,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6217,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6290,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6377,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..4bbbab6431 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,378 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..26e8c131fd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,136 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From acef69449a1c8f81f6b69f580585bf6923e84d51 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From 9472024ef0de1056e91c559277fc0deedd7a79e8 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5d8d583ddc..dc79cbb4db 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From c76bb70c489d3f49acefa69ec0eee5d18771ecc8 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 706 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1544 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..507f3cb1cc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8303aad35f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index dc79cbb4db..c39fd37b7f 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..1223a9775d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3329,9 +3565,51 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying infinite interval by finite number keeps it infinite but
+	 * may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (is_factor_inf)
+	{
+		Interval	zero;
+		int			result_is_inf;
+
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * is_factor_inf;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3670,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3706,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3750,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4038,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4185,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4338,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4526,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4769,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5119,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5393,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5633,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5710,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5980,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6217,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6290,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6377,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..4bbbab6431 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,378 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..26e8c131fd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,136 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From 7da4853f9a68242087ecdc95a17ab02e95cfda92 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5d8d583ddc..dc79cbb4db 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 98fb6780e3c3599523de19284cb0434e25b1ca82 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 708 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1546 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..507f3cb1cc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0b62e0c828..c14b30040f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index dc79cbb4db..c39fd37b7f 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..509e03ed04 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3329,9 +3565,53 @@ interval_mul(PG_FUNCTION_ARGS)
 	int32		orig_month = span->month,
 				orig_day = span->day;
 	Interval   *result;
+	int			is_factor_inf = isinf(factor);
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results in an 
+	 * infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			result_is_inf;
+		int			factor_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3672,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3708,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3752,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4040,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4187,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4340,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4528,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4771,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5121,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5395,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5635,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5712,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5982,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6219,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6292,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6379,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..4bbbab6431 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,378 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..26e8c131fd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,136 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 28743c5390a76b91abc6ff9ad37d4efb81bca040 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From 7da4853f9a68242087ecdc95a17ab02e95cfda92 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5d8d583ddc..dc79cbb4db 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 41064a220e04855bcd1070941069b6054c4fa0ee Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 707 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1545 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..507f3cb1cc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0b62e0c828..c14b30040f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index dc79cbb4db..c39fd37b7f 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..b95346f6ec 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results in an 
+	 * infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_is_inf;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..4bbbab6431 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,378 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..26e8c131fd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,136 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 28743c5390a76b91abc6ff9ad37d4efb81bca040 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From 9a1a712d296e394d39f21f5047f922177563ce7b Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/3] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5d8d583ddc..dc79cbb4db 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From 9bba1af3f9411cf109368817214e987d9b89237a Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/3] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 28b71d9681..db5c7b83ba 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 56feda1a3d..434fd87a35 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From f506833c3b79cc7f6aae3e5e21aee445e83079a1 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/3] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 707 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1545 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..507f3cb1cc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 5a47ce4343..8303aad35f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9472,7 +9472,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10369,7 +10369,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index dc79cbb4db..c39fd37b7f 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3550,6 +3550,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 			case DTK_STRING:
 			case DTK_SPECIAL:
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e6246dc44b..8c739833dc 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4145,7 +4145,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..02587e5f93 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_is_inf;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_is_inf = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_is_inf == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_is_inf < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index db5c7b83ba..4bbbab6431 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,3 +1851,378 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 434fd87a35..26e8c131fd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -587,3 +594,136 @@ SELECT f1,
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From 7e5ec988a6a300ff458a13b514920471433a1408 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/4] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e041b..96db07c3b4 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508d0..f328b8914d 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From 74d2b7e42f72c2727f35aec9a1d68a8a6e738bdd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/4] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..48fc0d5942 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From c3c8708c0ddfa1c1e256af46c153ba740606dac3 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH 4/4] Revert "Remove dead code in DecodeInterval()"

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5fed7e3dd1..5b8b080a32 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3582,6 +3582,11 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
-- 
2.25.1

From 9d95c38c39c026719505934031c372429c4a2793 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/4] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 707 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1545 insertions(+), 206 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..507f3cb1cc 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..7786853743 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 48fc0d5942..5fed7e3dd1 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3557,6 +3557,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef97..e9e85503f8 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..3100ad610f 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 96db07c3b4..a4630d17ef 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,6 +1851,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f328b8914d..023cf3761a 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -588,6 +595,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From 71908c3d8a06f405c27e2e09927c66bbafb5d80b Mon Sep 17 00:00:00 2001
From: pgaddict <jian.universality@gmail.com>
Date: Fri, 15 Sep 2023 16:38:03 +0800
Subject: [PATCH v20 5/6] doc for special interval value.

interval now have special values: infinity and -infinity.
document it.
---
 doc/src/sgml/datatype.sgml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 507f3cb1..c2aac35f 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,12 +2320,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>timestamptz</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>timestamptz</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
-- 
2.34.1

From 17cee14a9eae900ff168dd40de30d9a370e5bd4e Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH v20 4/6] Revert "Remove dead code in DecodeInterval()"

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5fed7e3d..5b8b080a 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3582,6 +3582,11 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
-- 
2.34.1

From 93ffbeb2b10cec642e855b960d76aba62f8a2496 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH v20 2/6] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec..3ab9b691 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65..48ef4955 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89..1a639058 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e04..96db07c3 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508..f328b891 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From 6984586effbaad33b895b7c41064835f5f10a0b3 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH v20 3/6] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 709 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1546 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9..507f3cb1 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f9..77868537 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de..f2107dd9 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 48fc0d59..5fed7e3d 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3557,6 +3557,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef..e9e85503 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd007..6e871738 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b691..3100ad61 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->month = 0;
-	result->day = 0;
-
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
 	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		result->month = 0;
+		result->day = 0;
+
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a639058..f9bd30d2 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8..fe713fb6 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30..eaf44b96 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 96db07c3..a4630d17 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,6 +1851,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c..53542e07 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c..825202d5 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2..0b4071f3 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f328b891..023cf376 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -588,6 +595,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9c..ea12ffd1 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d04..7876225c 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From 6b10acce408d5967ab67e2d6d52342ac3ebc905c Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH v20 1/6] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37..48fc0d59 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 45080089..81726c65 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 0d1ca2f1ee2ef76bab1927b59a2f45b0f20d5c79 Mon Sep 17 00:00:00 2001
From: pgaddict <jian.universality@gmail.com>
Date: Fri, 15 Sep 2023 17:28:29 +0800
Subject: [PATCH v20 6/6] refactor avg(interval), sum(interval) aggregate.

to make avg(interval), sum(interval) window function also work
when intervals have special values: inf/-inf,
We need a state to live through the whole aggregate function cycle.
the state will accumulate or discard value.
the aggregate transition and inverse transition function associated
with interval type will update the state all the time.
the aggregate final function will compute the final result.
We already do the same logic in many data types like numeric.

so invent a new struct: IntervalAggState.
it will be initialized in aggregate memory context
(I don't know when it will be destroyed).
For avg(interval), sum(interval) every time accumulate a new interval value,
change the state struct inner
elements value.
In IntervalAggStat we also track the number of special values.
In the end, using the aggregate final function returns the result.
To make window function work,
we need to have an inverse transition function that can discard an interval from the state.

tests include order by and non-order by window function case.
also invent the sum(interval) aggregate final function.
---
 src/backend/utils/adt/timestamp.c    | 455 +++++++++++++++++++--------
 src/include/catalog/pg_aggregate.dat |  21 +-
 src/include/catalog/pg_proc.dat      |  21 +-
 src/test/regress/expected/window.out |  64 ++++
 src/test/regress/sql/window.sql      |  45 +++
 5 files changed, 452 insertions(+), 154 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3100ad61..8fe1b60d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,7 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+typedef struct IntervalAggState
+{
+	MemoryContext agg_context;	/* context we're calculating in */
+	int64		N;				/* count of processed numbers */
+	Interval sumX;				/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use INF_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
 
+#define INF_TOTAL_COUNT(na) \
+	((na)->N + (na)->pInfcount + (na)->nInfcount)
+
+static void do_interval_accum(IntervalAggState *state, Interval *newval);
+static IntervalAggState *makeIntervalAggState(FunctionCallInfo fcinfo);
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
 static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
@@ -3860,161 +3874,328 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for a interval aggregate function that needs to compute
+ * sum, count, avg.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+	state->agg_context = agg_context;
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * actual do the interval accumualation.
+ * if to be added interval value is not finite then record.
+ * state's infinity/-infinity count, else do interval addidition.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+
+	Interval	*X;
+	Interval	*p;
+/* i think if temp as interval pointer, following interval addition will not work.*/
+	Interval	temp;
+	MemoryContext old_context;
+
+	X = (Interval *) palloc(sizeof(Interval));
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN (newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	X->day = newval->day;
+	X->month = newval->month;
+	X->time = newval->time;
+
+	temp.day = state->sumX.day;
+	temp.month = state->sumX.month;
+	temp.time = state->sumX.time;
+
+	/* The rest of this needs to work in the aggregate context */
+	old_context = MemoryContextSwitchTo(state->agg_context);
+
+	state->N++;
+
+	/* Accumulate sums */
+	p = &state->sumX;
+	{
+		p->month = temp.month + X->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(temp.month, X->month) &&
+			!SAMESIGN(p->month, temp.month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		p->day = temp.day + X->day;
+		if (SAMESIGN(temp.day, X->day) &&
+			!SAMESIGN(p->day, temp.day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		p->time = temp.time + X->time;
+		if (SAMESIGN(temp.time, X->time) &&
+			!SAMESIGN(p->time, temp.time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+
+	MemoryContextSwitchTo(old_context);
+	return;
+}
+
+/*
+ * transition function for AVG(interval) aggregate.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
+
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/*
+ *combine function to conmbine 2 interval aggreagte state.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		old_context = MemoryContextSwitchTo(agg_context);
+
+		state1 = makeIntervalAggState(fcinfo);
+		state1->agg_context = CurrentMemoryContext;
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+
+		state1->sumX.day =  state2->sumX.day;
+		state1->sumX.month =  state2->sumX.month;
+		state1->sumX.time =  state2->sumX.time;
+
+		MemoryContextSwitchTo(old_context);
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		/* The rest of this needs to work in the aggregate context */
+		old_context = MemoryContextSwitchTo(agg_context);
+
+		/* Accumulate interval values */
+		do_interval_accum(state1, &state2->sumX);
+
+		MemoryContextSwitchTo(old_context);
+	}
+	PG_RETURN_POINTER(state1);
+}
+
+static bool
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	Interval	*X;
+	MemoryContext old_context;
+
+	X = (Interval *) palloc(sizeof(Interval));
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN (newval))
+	{
+		state->nInfcount--;
+		return true;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return true;
+	}
+
+	/* the value to be discarded is not special. assign to X */
+	X->day = -newval->day;
+	X->month = -newval->month;
+	X->time = -newval->time;
+
+	state->N--;
+	if (state->N > 0)
+	{
+		/* The rest of this needs to work in the aggregate context */
+		old_context = MemoryContextSwitchTo(state->agg_context);
+
+		do_interval_accum(state,X);
+
+		/* do_interval_accum increase state->N by one, we need decrease one */
+		state->N--;
+		MemoryContextSwitchTo(old_context);
+	}
+	else
+	{
+		/*now all values discarded, reset now */
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+
+	return true;
+}
+
+/*
+ * Generic inverse transition function for interval aggregates
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
  */
-
-Datum
-interval_accum(PG_FUNCTION_ARGS)
-{
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
-
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
-
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
-
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
-
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
-
-	PG_RETURN_ARRAYTYPE_P(result);
-}
-
-Datum
-interval_combine(PG_FUNCTION_ARGS)
-{
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
-
-	Interval   *newsum;
-	ArrayType  *result;
-
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
-
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
-
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
-
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
-
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
-
-	PG_RETURN_ARRAYTYPE_P(result);
-}
-
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+	{
+		/* If we fail to perform the inverse transition, return NULL */
+		if (!do_interval_discard(state, PG_GETARG_INTERVAL_P(1)))
+			PG_RETURN_NULL();
+	}
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
-
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
-
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/* avg(interval) aggregate final function */
 Datum
 interval_avg(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
-
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	IntervalAggState *state;
+	double		N_datum;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || INF_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range."))); /* maybe we should make it more verbose */
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = (double) state->N;
+	sumX	= &state->sumX;
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div,  IntervalPGetDatum(sumX), Float8GetDatum(N_datum)));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || INF_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/* adding plus and minus infinities should yield error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range."))); /* maybe we should make it more verbose */
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	sumX = &state->sumX;
+	PG_RETURN_INTERVAL_P(sumX);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d..905359b3 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,12 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +72,11 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9805bc61..92857368 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -2356,6 +2356,7 @@
 { oid => '1169',
   proname => 'interval_pl', prorettype => 'interval',
   proargtypes => 'interval interval', prosrc => 'interval_pl' },
+
 { oid => '1170',
   proname => 'interval_mi', prorettype => 'interval',
   proargtypes => 'interval interval', prosrc => 'interval_mi' },
@@ -4914,17 +4915,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df1..85b21d7a 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,70 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum | curr_next_avg | prev1_curr_avg 
+-----------+---------------+----------------+---------------+----------------
+ -infinity | -infinity     | -infinity      | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity      | infinity      | -infinity
+ infinity  | infinity      | infinity       | infinity      | infinity
+ infinity  | infinity      | infinity       | infinity      | infinity
+           |               | infinity       |               | infinity
+           |               |                |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92a..d23370a1 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,51 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
-- 
2.34.1

From 076611d9813cbb6fc62f61f8dcf773ef8de2f515 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH v21 1/6] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37..48fc0d59 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 45080089..81726c65 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.34.1

From 45d801e4fc8f0de9aa4039f315e8e922493db187 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH v21 2/6] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec..3ab9b691 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65..48ef4955 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89..1a639058 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e04..96db07c3 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508..f328b891 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.34.1

From 2c61ea5039a5d603c8c723157b9fdf1c196117af Mon Sep 17 00:00:00 2001
From: pgaddict <jian.universality@gmail.com>
Date: Fri, 15 Sep 2023 16:38:03 +0800
Subject: [PATCH v21 5/6] doc for special interval value.

interval now have special values: infinity and -infinity.
document it.
---
 doc/src/sgml/datatype.sgml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 507f3cb1..c2aac35f 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,12 +2320,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
-- 
2.34.1

From 7992f2ec0dc2c957822ca0fe6280700e297a7501 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH v21 3/6] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   2 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 709 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1546 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9..507f3cb1 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,7 +2320,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f9..77868537 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de..f2107dd9 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 48fc0d59..5fed7e3d 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3557,6 +3557,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef..e9e85503 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd007..6e871738 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b691..3100ad61 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->month = 0;
-	result->day = 0;
-
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
 	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		result->month = 0;
+		result->day = 0;
+
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a639058..f9bd30d2 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8..fe713fb6 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30..eaf44b96 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 96db07c3..a4630d17 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,6 +1851,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c..53542e07 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c..825202d5 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2..0b4071f3 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f328b891..023cf376 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -588,6 +595,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9c..ea12ffd1 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d04..7876225c 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.34.1

From c5bd5799e35a33cf647b2a957972285dd885b9cb Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH v21 4/6] Revert "Remove dead code in DecodeInterval()"

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5fed7e3d..5b8b080a 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3582,6 +3582,11 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
-- 
2.34.1

From adc1e06fa74d00f3ab069434ba720486393b44d3 Mon Sep 17 00:00:00 2001
From: pgaddict <jian.universality@gmail.com>
Date: Wed, 20 Sep 2023 18:08:33 +0800
Subject: [PATCH v21 6/6] refactor avg(interval), sum(interval) aggregate.

To make avg(interval), sum(interval) window function also work
when intervals have special values: inf/-inf,
We need a state to live through the whole aggregate function cycle.
the state will accumulate or discard value.
the aggregate transition and inverse transition function associated
with interval type will update the state all the time.
the aggregate final function will compute the final result.
We already do the same logic in many data types like numeric.

so invent a new struct: IntervalAggState.
it will be initialized in aggregate memory context
(I don't know when it will be destroyed).
For avg(interval), sum(interval) every time accumulate a new interval value,
change the state struct inner
elements value.
In IntervalAggStat we also track the number of special values.
In the end, using the aggregate final function returns the result.
To make window function work,
we need to have an inverse transition function that can discard an interval from the state.

tests include order by and non-order by window function case.
also invent the sum(interval) aggregate final function.
---
 src/backend/utils/adt/timestamp.c    | 452 +++++++++++++++++++--------
 src/include/catalog/pg_aggregate.dat |  21 +-
 src/include/catalog/pg_proc.dat      |  21 +-
 src/test/regress/expected/window.out |  64 ++++
 src/test/regress/sql/window.sql      |  45 +++
 5 files changed, 449 insertions(+), 154 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3100ad61..d9fc812b 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,7 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+typedef struct IntervalAggState
+{
+	MemoryContext agg_context;	/* context we're calculating in */
+	int64		N;				/* count of processed intervals */
+	Interval sumX;				/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use INF_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
 
+#define INF_TOTAL_COUNT(na) \
+	((na)->N + (na)->pInfcount + (na)->nInfcount)
+
+static void do_interval_accum(IntervalAggState *state, Interval *newval);
+static IntervalAggState *makeIntervalAggState(FunctionCallInfo fcinfo);
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
 static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
@@ -3860,161 +3874,325 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for a interval aggregate function that needs to compute
+ * sum, count, avg.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+	state->agg_context = agg_context;
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * actual do the interval accumualation.
+ * if to be added interval value is not finite then record.
+ * state's infinity/-infinity count, else do interval addidition.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+
+	Interval	X;
+	Interval	*p;
+/* i think if temp as interval pointer, following interval addition will not work.*/
+	Interval	temp;
+	MemoryContext old_context;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN (newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	X.day = newval->day;
+	X.month = newval->month;
+	X.time = newval->time;
+
+	temp.day = state->sumX.day;
+	temp.month = state->sumX.month;
+	temp.time = state->sumX.time;
+
+	/* The rest of this needs to work in the aggregate context */
+	old_context = MemoryContextSwitchTo(state->agg_context);
+
+	state->N++;
+
+	/* Accumulate interval struct field */
+	p = &state->sumX;
+	{
+		/* overflow check copied from int8pl */
+		if (unlikely(pg_add_s64_overflow(temp.time, X.time, &p->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		/* overflow check copied from int4pl */
+		p->month = temp.month + X.month;
+		if (SAMESIGN(temp.month, X.month) &&
+			!SAMESIGN(p->month, temp.month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		p->day = temp.day + X.day;
+		if (SAMESIGN(temp.day, X.day) &&
+			!SAMESIGN(p->day, temp.day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+
+	MemoryContextSwitchTo(old_context);
+	return;
+}
+
+/*
+ * transition function for AVG(interval) aggregate.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
+
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/*
+ *combine function to conmbine 2 interval aggreagte state.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		old_context = MemoryContextSwitchTo(agg_context);
+
+		state1 = makeIntervalAggState(fcinfo);
+		state1->agg_context = CurrentMemoryContext;
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+		state1->sumX.time =  state2->sumX.time;
+		state1->sumX.day =  state2->sumX.day;
+		state1->sumX.month =  state2->sumX.month;
+
+		MemoryContextSwitchTo(old_context);
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		/* The rest of this needs to work in the aggregate context */
+		old_context = MemoryContextSwitchTo(agg_context);
+
+		/* Accumulate interval values */
+		do_interval_accum(state1, &state2->sumX);
+
+		MemoryContextSwitchTo(old_context);
+	}
+	PG_RETURN_POINTER(state1);
+}
+
+static bool
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	Interval	X;
+	MemoryContext old_context;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN (newval))
+	{
+		state->nInfcount--;
+		return true;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return true;
+	}
+
+	/* the value to be discarded is not special. assign to X */
+	X.time = -newval->time;
+	X.day = -newval->day;
+	X.month = -newval->month;
+
+	state->N--;
+	if (state->N > 0)
+	{
+		/* The rest of this needs to work in the aggregate context */
+		old_context = MemoryContextSwitchTo(state->agg_context);
+
+		do_interval_accum(state,&X);
+
+		/* do_interval_accum increase state->N by one, we need decrease one */
+		state->N--;
+		MemoryContextSwitchTo(old_context);
+	}
+	else
+	{
+		/*now all values discarded, reset now.
+		* due to NULL, div by zero cases
+		* we can only memset interval struct.
+		*/
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+
+	return true;
+}
+
+/*
+ * Generic inverse transition function for interval aggregates
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
  */
-
-Datum
-interval_accum(PG_FUNCTION_ARGS)
-{
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
-
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
-
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
-
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
-
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
-
-	PG_RETURN_ARRAYTYPE_P(result);
-}
-
-Datum
-interval_combine(PG_FUNCTION_ARGS)
-{
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
-
-	Interval   *newsum;
-	ArrayType  *result;
-
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
-
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
-
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
-
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
-
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
-
-	PG_RETURN_ARRAYTYPE_P(result);
-}
-
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+	{
+		/* If we fail to perform the inverse transition, return NULL */
+		if (!do_interval_discard(state, PG_GETARG_INTERVAL_P(1)))
+			PG_RETURN_NULL();
+	}
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
-
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
-
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/* avg(interval) aggregate final function */
 Datum
 interval_avg(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
-
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
-
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	IntervalAggState *state;
+	int64		N_datum;
+	Interval   *sumX;
+	Datum	d;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || INF_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range."))); /* maybe we should make it more verbose */
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = state->N;
+	sumX	= &state->sumX;
+	d = DirectFunctionCall1(i8tod,Int64GetDatum(N_datum));
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div,  IntervalPGetDatum(sumX), d));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || INF_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/* adding plus and minus infinities should yield error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range."))); /* maybe we should make it more verbose */
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	sumX = &state->sumX;
+	PG_RETURN_INTERVAL_P(sumX);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d..905359b3 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,12 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +72,11 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9805bc61..92857368 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -2356,6 +2356,7 @@
 { oid => '1169',
   proname => 'interval_pl', prorettype => 'interval',
   proargtypes => 'interval interval', prosrc => 'interval_pl' },
+
 { oid => '1170',
   proname => 'interval_mi', prorettype => 'interval',
   proargtypes => 'interval interval', prosrc => 'interval_mi' },
@@ -4914,17 +4915,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df1..85b21d7a 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,70 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum | curr_next_avg | prev1_curr_avg 
+-----------+---------------+----------------+---------------+----------------
+ -infinity | -infinity     | -infinity      | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity      | infinity      | -infinity
+ infinity  | infinity      | infinity       | infinity      | infinity
+ infinity  | infinity      | infinity       | infinity      | infinity
+           |               | infinity       |               | infinity
+           |               |                |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92a..d23370a1 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,51 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
-- 
2.34.1

From bb51c8162c6ae84d94e3ab42de55fa6198aea2fe Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH 4/5] Introduce 'infinity' interval specification in
 DecodeInterval()

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Infinte interval specification i.e. "+infinity", "-infinity" or
"infinity" does not require anything other that one of the three
strings. Fix DecodeInterval() to disallow anything else.

"ago" may be used to revrse the sign of infinity specification like how
ago reverts the sign of finite intervals. But that is not as intuitive
as it is with finite intervals. Hence disallows "infinity ago" as well.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       | 24 ++++++++++++++++
 src/test/regress/expected/interval.out | 39 ++++++++++++++++++++++++++
 src/test/regress/sql/interval.sql      | 14 +++++++++
 3 files changed, 77 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5fed7e3dd1..b25bd6a551 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3254,6 +3254,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3582,6 +3585,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * infinity can not be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but that signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index a4630d17ef..d61b07f38e 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2244,3 +2244,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 023cf3761a..183ddfaf31 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -735,3 +735,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
-- 
2.25.1

From 7e5ec988a6a300ff458a13b514920471433a1408 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/5] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e041b..96db07c3b4 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508d0..f328b8914d 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From 74d2b7e42f72c2727f35aec9a1d68a8a6e738bdd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/5] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..48fc0d5942 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From 292e252183d4238eb96cab556cbadd224877c8b4 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 20 Sep 2023 15:41:00 +0530
Subject: [PATCH 5/5] Support infinite interval values in sum and avg window
 functions

Results of arithmetic operations involing both infinity and -infinity
intervals are undefined. Sliding window functions
accumulate and discard values as the window slides through the data.
Even if the data may have both infinities, none of windows may have both
of them together and thus produce definite results. Hence we can not use
normal operator functions to accumulate and discard values. Instead we
maintain a count of both infinities seen respectively in an aggregate
state and compute the aggregate for each window based on the accumulated
finite value and the counts of infinities, all of which are updated as
the window slides through the data.

Initial patch by Jian He, significantly edited by Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 407 ++++++++++++++++++---------
 src/include/catalog/pg_aggregate.dat |  23 +-
 src/include/catalog/pg_proc.dat      |  20 +-
 src/test/regress/expected/window.out |  62 ++++
 src/test/regress/sql/window.sql      |  43 +++
 src/tools/pgindent/typedefs.list     |   1 +
 6 files changed, 400 insertions(+), 156 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3100ad610f..c6dc2d4423 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,6 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as Internal. It's
+ * a pointer to a NumericAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of processed intervals */
+	Interval	sumX;			/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -82,6 +97,8 @@ static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
 static void interval_um_internal(Interval *interval, Interval *result);
+static void finite_interval_pl(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3447,34 +3464,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-	{
-		result->month = span1->month + span2->month;
-		/* overflow check copied from int4pl */
-		if (SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day + span2->day;
-		if (SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time + span2->time;
-		if (SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_pl(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3860,161 +3850,300 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function that needs to compute
+ * sum and count.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Function to add two finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * We handle non-finite intervals in different ways when accumulating intervals
+ * and adding two intervals respectively. But the addition of finite interval
+ * has same implementation in both these cases.
  */
+static void
+finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
-Datum
-interval_accum(PG_FUNCTION_ARGS)
+	result->month = span1->month + span2->month;
+	/* overflow check copied from int4pl */
+	if (SAMESIGN(span1->month, span2->month) &&
+		!SAMESIGN(result->month, span1->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = span1->day + span2->day;
+	if (SAMESIGN(span1->day, span2->day) &&
+		!SAMESIGN(result->day, span1->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->time = span1->time + span2->time;
+	if (SAMESIGN(span1->time, span2->time) &&
+		!SAMESIGN(result->time, span1->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	Interval	temp;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	memcpy(&temp, &state->sumX, sizeof(Interval));
+	finite_interval_pl(&state->sumX, &temp, newval);
+	state->N++;
+}
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+/*
+ * Transition function for interval aggregates.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/*
+ * Combine function for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_combine(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
 
-	Interval   *newsum;
-	ArrayType  *result;
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		state1 = makeIntervalAggState(fcinfo);
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		Interval	temp;
+
+		/* Accumulate interval values */
+		memcpy(&temp, &state1->sumX, sizeof(Interval));
+		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
+	}
+
+	PG_RETURN_POINTER(state1);
+}
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* Handle to be discarded finite value. */
+	if (state->N > 0)
+	{
+		Interval	temp;
+		Interval	neg_val;
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+		neg_val.day = -newval->day;
+		neg_val.month = -newval->month;
+		neg_val.time = -newval->time;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+		memcpy(&temp, &state->sumX, sizeof(Interval));
+		finite_interval_pl(&state->sumX, &temp, &neg_val);
+	}
+	else
+	{
+		/* All values discarded, reset the state */
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+	state->N--;
 }
 
+/*
+ * Generic inverse transition function for interval aggregates
+ */
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	double		N_datum;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = (double) state->N;
+	sumX = &state->sumX;
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
+										Float8GetDatum(N_datum)));
 }
 
+/* sum(interval) aggregate final function */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_sum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+	Interval   *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	result = (Interval *) palloc(sizeof(Interval));
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
-}
+	/* adding plus and minus interval infinities is not possible */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
 
+	memcpy(result, &state->sumX, sizeof(Interval));
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e2087d7be1 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,12 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9805bc6118..f8eca58ddf 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4914,17 +4914,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..45262924cd 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,68 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum 
+-----------+---------------+----------------
+ -infinity | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity
+ infinity  | infinity      | infinity
+ infinity  | infinity      | infinity
+           |               | infinity
+           |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..d00423946d 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,49 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f3d8a2a855..4df61a69ca 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1204,6 +1204,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.25.1

From 9442b707b6aec49da063ae1714716325cef826dd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/5] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   4 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 707 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1546 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..557b81cae8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,12 +2320,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..7786853743 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 48fc0d5942..5fed7e3dd1 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3557,6 +3557,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef97..e9e85503f8 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..3100ad610f 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 96db07c3b4..a4630d17ef 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,6 +1851,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f328b8914d..023cf3761a 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -588,6 +595,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From bff5e3dfa8607a8b45aa287a7c55fda9d984f339 Mon Sep 17 00:00:00 2001
From: pgaddict <jian.universality@gmail.com>
Date: Thu, 21 Sep 2023 10:05:21 +0800
Subject: [PATCH v22 7/7] interval aggregate serializatinn and deserialization

add interval aggregate serialization and deserialization function.
fix a typo.
change manually negate a interval to use interval_um_internal.
---
 src/backend/utils/adt/timestamp.c    | 86 +++++++++++++++++++++++++---
 src/include/catalog/pg_aggregate.dat |  4 ++
 src/include/catalog/pg_proc.dat      |  6 ++
 3 files changed, 88 insertions(+), 8 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index c6dc2d44..2b86171a 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -75,7 +75,7 @@ typedef struct
 
 /*
  * The transition datatype for interval aggregates is declared as Internal. It's
- * a pointer to a NumericAggState allocated in the aggregate context.
+ * a pointer to a IntervalAggState allocated in the aggregate context.
  */
 typedef struct IntervalAggState
 {
@@ -3984,10 +3984,7 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 		state1->N = state2->N;
 		state1->pInfcount = state2->pInfcount;
 		state1->nInfcount = state2->nInfcount;
-
-		state1->sumX.day = state2->sumX.day;
-		state1->sumX.month = state2->sumX.month;
-		state1->sumX.time = state2->sumX.time;
+		memcpy(&state1->sumX, &state2->sumX, sizeof(Interval));
 
 		PG_RETURN_POINTER(state1);
 	}
@@ -4008,6 +4005,81 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_serialize(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+	pq_begintypsend(&buf);
+	/* N */
+	pq_sendint64(&buf, state->N);
+	/* Interval struct elements, one by one. */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
+	result = pq_endtypsend(&buf);
+	PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_deserialize(PG_FUNCTION_ARGS)
+{
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	sstate = PG_GETARG_BYTEA_PP(0);
+
+	/*
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
+	 */
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+	result = makeIntervalAggState(fcinfo);
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
+
+	/* Interval struct elements, one by one. */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
+	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+	pfree(buf.data);
+
+	PG_RETURN_POINTER(result);
+}
+
 /*
  * Remove the given interval value from the aggregated state.
  */
@@ -4034,9 +4106,7 @@ do_interval_discard(IntervalAggState *state, Interval *newval)
 		Interval	temp;
 		Interval	neg_val;
 
-		neg_val.day = -newval->day;
-		neg_val.month = -newval->month;
-		neg_val.time = -newval->time;
+		interval_um_internal(newval, &neg_val);
 
 		memcpy(&temp, &state->sumX, sizeof(Interval));
 		finite_interval_pl(&state->sumX, &temp, &neg_val);
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index e2087d7b..0e62c3f7 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -45,6 +45,8 @@
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
 { aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
@@ -75,6 +77,8 @@
   aggtranstype => 'money', aggmtranstype => 'money' },
 { aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8eca58d..486573d6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4943,6 +4943,12 @@
 { oid => '3571', descr => 'aggregate transition function',
   proname => 'int4_avg_accum_inv', prorettype => '_int8',
   proargtypes => '_int8 int4', prosrc => 'int4_avg_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1964', descr => 'aggregate final function',
   proname => 'int8_avg', prorettype => 'numeric', proargtypes => '_int8',
   prosrc => 'int8_avg' },
-- 
2.34.1

From bb51c8162c6ae84d94e3ab42de55fa6198aea2fe Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH 4/7] Introduce 'infinity' interval specification in
 DecodeInterval()

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Infinte interval specification i.e. "+infinity", "-infinity" or
"infinity" does not require anything other that one of the three
strings. Fix DecodeInterval() to disallow anything else.

"ago" may be used to revrse the sign of infinity specification like how
ago reverts the sign of finite intervals. But that is not as intuitive
as it is with finite intervals. Hence disallows "infinity ago" as well.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       | 24 ++++++++++++++++
 src/test/regress/expected/interval.out | 39 ++++++++++++++++++++++++++
 src/test/regress/sql/interval.sql      | 14 +++++++++
 3 files changed, 77 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5fed7e3dd1..b25bd6a551 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3254,6 +3254,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3582,6 +3585,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * infinity can not be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but that signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index a4630d17ef..d61b07f38e 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2244,3 +2244,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 023cf3761a..183ddfaf31 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -735,3 +735,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
-- 
2.25.1

From 6f49ea0ab7cbe8c4cca6850d8253cddf86c7dd7c Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 16:52:30 +0530
Subject: [PATCH 7/7] Implement serialization functions for interval aggregate
 state

Now that interval aggregates use transition state which of date type Internal,
parallel aggregates require these separate functions.

Jian He, reviewed by Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 78 ++++++++++++++++++++++++++++
 src/include/catalog/pg_aggregate.dat |  4 ++
 src/include/catalog/pg_proc.dat      |  6 +++
 3 files changed, 88 insertions(+)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 17415cc4bd..31fd5d9e07 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -4004,6 +4004,84 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_serialize(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
+
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	/* TODO: Handle NULL inputs? */
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+	pq_begintypsend(&buf);
+	/* N */
+	pq_sendint64(&buf, state->N);
+	/* Finite interval value */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
+	result = pq_endtypsend(&buf);
+	PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_deserialize(PG_FUNCTION_ARGS)
+{
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	sstate = PG_GETARG_BYTEA_PP(0);
+
+	/*
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
+	 */
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+	result = makeIntervalAggState(fcinfo);
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
+
+	/* Interval struct elements, one by one. */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
+	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+	pfree(buf.data);
+
+	PG_RETURN_POINTER(result);
+}
+
 /*
  * Remove the given interval value from the aggregated state.
  */
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index e2087d7be1..0e62c3f7a6 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -45,6 +45,8 @@
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
 { aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
@@ -75,6 +77,8 @@
   aggtranstype => 'money', aggmtranstype => 'money' },
 { aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8eca58ddf..34da5f3687 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4925,6 +4925,12 @@
   proname => 'interval_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
   prosrc => 'interval_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
-- 
2.25.1

From c96cb360f5ce4a71f24f9dd12fbc10b9713f89b8 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 20 Sep 2023 15:41:00 +0530
Subject: [PATCH 5/7] Support infinite interval values in sum and avg window
 functions

Results of arithmetic operations involing both infinity and -infinity
intervals are undefined. Sliding window functions
accumulate and discard values as the window slides through the data.
Even if the data may have both infinities, none of windows may have both
of them together and thus produce definite results. Hence we can not use
normal operator functions to accumulate and discard values. Instead we
maintain a count of both infinities seen respectively in an aggregate
state and compute the aggregate for each window based on the accumulated
finite value and the counts of infinities, all of which are updated as
the window slides through the data.

Initial patch by Jian He, significantly edited by Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 407 ++++++++++++++++++---------
 src/include/catalog/pg_aggregate.dat |  23 +-
 src/include/catalog/pg_proc.dat      |  20 +-
 src/test/regress/expected/window.out |  62 ++++
 src/test/regress/sql/window.sql      |  43 +++
 src/tools/pgindent/typedefs.list     |   1 +
 6 files changed, 400 insertions(+), 156 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3100ad610f..21478c387c 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,6 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as Internal. It's
+ * a pointer to a IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of processed intervals */
+	Interval	sumX;			/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -82,6 +97,8 @@ static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
 static void interval_um_internal(Interval *interval, Interval *result);
+static void finite_interval_pl(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3447,34 +3464,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-	{
-		result->month = span1->month + span2->month;
-		/* overflow check copied from int4pl */
-		if (SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day + span2->day;
-		if (SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time + span2->time;
-		if (SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_pl(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3860,161 +3850,300 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function that needs to compute
+ * sum and count.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Function to add two finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * We handle non-finite intervals in different ways when accumulating intervals
+ * and adding two intervals respectively. But the addition of finite interval
+ * has same implementation in both these cases.
  */
+static void
+finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
-Datum
-interval_accum(PG_FUNCTION_ARGS)
+	result->month = span1->month + span2->month;
+	/* overflow check copied from int4pl */
+	if (SAMESIGN(span1->month, span2->month) &&
+		!SAMESIGN(result->month, span1->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = span1->day + span2->day;
+	if (SAMESIGN(span1->day, span2->day) &&
+		!SAMESIGN(result->day, span1->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->time = span1->time + span2->time;
+	if (SAMESIGN(span1->time, span2->time) &&
+		!SAMESIGN(result->time, span1->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	Interval	temp;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	memcpy(&temp, &state->sumX, sizeof(Interval));
+	finite_interval_pl(&state->sumX, &temp, newval);
+	state->N++;
+}
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+/*
+ * Transition function for interval aggregates.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/*
+ * Combine function for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_combine(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
 
-	Interval   *newsum;
-	ArrayType  *result;
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		state1 = makeIntervalAggState(fcinfo);
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		Interval	temp;
+
+		/* Accumulate interval values */
+		memcpy(&temp, &state1->sumX, sizeof(Interval));
+		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
+	}
+
+	PG_RETURN_POINTER(state1);
+}
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* Handle to be discarded finite value. */
+	if (state->N > 0)
+	{
+		Interval	temp;
+		Interval	neg_val;
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+		neg_val.day = -newval->day;
+		neg_val.month = -newval->month;
+		neg_val.time = -newval->time;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+		memcpy(&temp, &state->sumX, sizeof(Interval));
+		finite_interval_pl(&state->sumX, &temp, &neg_val);
+	}
+	else
+	{
+		/* All values discarded, reset the state */
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+	state->N--;
 }
 
+/*
+ * Generic inverse transition function for interval aggregates
+ */
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	double		N_datum;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = (double) state->N;
+	sumX = &state->sumX;
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
+										Float8GetDatum(N_datum)));
 }
 
+/* sum(interval) aggregate final function */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_sum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+	Interval   *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	result = (Interval *) palloc(sizeof(Interval));
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
-}
+	/* adding plus and minus interval infinities is not possible */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
 
+	memcpy(result, &state->sumX, sizeof(Interval));
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e2087d7be1 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,12 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9805bc6118..f8eca58ddf 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4914,17 +4914,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..45262924cd 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,68 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum 
+-----------+---------------+----------------
+ -infinity | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity
+ infinity  | infinity      | infinity
+ infinity  | infinity      | infinity
+           |               | infinity
+           |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..d00423946d 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,49 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f3d8a2a855..4df61a69ca 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1204,6 +1204,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.25.1

From 9442b707b6aec49da063ae1714716325cef826dd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/7] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   4 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 707 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1546 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..557b81cae8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,12 +2320,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..7786853743 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 48fc0d5942..5fed7e3dd1 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3557,6 +3557,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef97..e9e85503f8 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..3100ad610f 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 96db07c3b4..a4630d17ef 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,6 +1851,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f328b8914d..023cf3761a 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -588,6 +595,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From 74d2b7e42f72c2727f35aec9a1d68a8a6e738bdd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/7] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..48fc0d5942 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From 7e5ec988a6a300ff458a13b514920471433a1408 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/7] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e041b..96db07c3b4 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508d0..f328b8914d 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From 12fbd8b15c963e1e69294ade4f6f5af6ef7b27c5 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 15:34:33 +0530
Subject: [PATCH 6/7] Use integer overflow checking routines to add and
 subtract finite intervals

Use pg_add/sub_s32/64_overflow() routines in finite_interval_pl() and
finite_interval_mi() instead of adding overflow checks in those
functions.

Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c      | 121 +++++++++++--------------
 src/test/regress/expected/interval.out |  11 +++
 src/test/regress/expected/window.out   |  54 ++++-------
 src/test/regress/sql/interval.sql      |   3 +
 src/test/regress/sql/window.sql        |  22 ++---
 5 files changed, 95 insertions(+), 116 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 21478c387c..17415cc4bd 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -99,6 +99,8 @@ static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 static void interval_um_internal(Interval *interval, Interval *result);
 static void finite_interval_pl(Interval *result, Interval *span1,
 							   Interval *span2);
+static void finite_interval_mi(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3506,34 +3508,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-	{
-		result->month = span1->month - span2->month;
-		/* overflow check copied from int4mi */
-		if (!SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day - span2->day;
-		if (!SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time - span2->time;
-		if (!SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_mi(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3873,11 +3848,18 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Function to add two finite intervals.
+ * Functions to add or subtract two finite intervals.
+ *
+ * We handle non-finite intervals in different ways when accumulating/discarding
+ * intervals and in actual mathematical operations respectively. But the
+ * addition or subtraction of finite intervals have same implementation
+ * respectively in both these cases.
+ *
+ * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
+ * to pass either of span1 or span2 as a result pointer. In such a case result
+ * will overwrite the given value.
  *
- * We handle non-finite intervals in different ways when accumulating intervals
- * and adding two intervals respectively. But the addition of finite interval
- * has same implementation in both these cases.
+ * If the result is not a valid interval, the function throws an error.
  */
 static void
 finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
@@ -3885,24 +3867,44 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
@@ -3919,9 +3921,6 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-
-	Interval	temp;
-
 	/* Count -infinity inputs separately from all else */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
@@ -3936,8 +3935,7 @@ do_interval_accum(IntervalAggState *state, Interval *newval)
 		return;
 	}
 
-	memcpy(&temp, &state->sumX, sizeof(Interval));
-	finite_interval_pl(&state->sumX, &temp, newval);
+	finite_interval_pl(&state->sumX, &state->sumX, newval);
 	state->N++;
 }
 
@@ -3963,6 +3961,9 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 
 /*
  * Combine function for interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in the
+ * first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3976,9 +3977,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	if (state2 == NULL)
 		PG_RETURN_POINTER(state1);
 
-	/* manually copy all fields from state2 to state1 */
 	if (state1 == NULL)
 	{
+		/* manually copy all fields from state2 to state1 */
 		state1 = makeIntervalAggState(fcinfo);
 
 		state1->N = state2->N;
@@ -3996,14 +3997,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	state1->pInfcount += state2->pInfcount;
 	state1->nInfcount += state2->nInfcount;
 
+	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-	{
-		Interval	temp;
-
-		/* Accumulate interval values */
-		memcpy(&temp, &state1->sumX, sizeof(Interval));
-		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
-	}
+		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4029,24 +4025,15 @@ do_interval_discard(IntervalAggState *state, Interval *newval)
 	}
 
 	/* Handle to be discarded finite value. */
+	state->N--;
 	if (state->N > 0)
-	{
-		Interval	temp;
-		Interval	neg_val;
-
-		neg_val.day = -newval->day;
-		neg_val.month = -newval->month;
-		neg_val.time = -newval->time;
-
-		memcpy(&temp, &state->sumX, sizeof(Interval));
-		finite_interval_pl(&state->sumX, &temp, &neg_val);
-	}
+		finite_interval_mi(&state->sumX, &state->sumX, newval);
 	else
 	{
 		/* All values discarded, reset the state */
+		Assert(state->N == 0);
 		memset(&state->sumX, 0, sizeof(state->sumX));
 	}
-	state->N--;
 }
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index d61b07f38e..c5587fc903 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -347,6 +347,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 45262924cd..63f36e069e 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,51 +4375,37 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-     x     | curr_next_avg | prev1_curr_sum 
------------+---------------+----------------
- -infinity | -infinity     | -infinity
- @ 6 days  | infinity      | -infinity
- infinity  | infinity      | infinity
- infinity  | infinity      | infinity
-           |               | infinity
-           |               | 
-(6 rows)
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
------------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
-           | infinity          | infinity      |                   |                | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
- @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
-           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
- -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
-(7 rows)
+                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
+----------------------------------------------+-------------------+-------------------+---------------+----------------
+                                              | infinity          |                   | infinity      | 
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
 
 --should fail.
 SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 183ddfaf31..e31c5c3d98 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -99,6 +99,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index d00423946d..6dd9885949 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,28 +1591,20 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
-- 
2.25.1

From 74d2b7e42f72c2727f35aec9a1d68a8a6e738bdd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:24 -0400
Subject: [PATCH 1/7] Move integer helper function to int.h

---
 src/backend/utils/adt/datetime.c | 25 ++++---------------------
 src/include/common/int.h         | 13 +++++++++++++
 2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..48fc0d5942 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -51,7 +51,6 @@ static int	DecodeDate(char *str, int fmask, int *tmask, bool *is2digits,
 					   struct pg_tm *tm);
 static char *AppendSeconds(char *cp, int sec, fsec_t fsec,
 						   int precision, bool fillzeros);
-static bool int64_multiply_add(int64 val, int64 multiplier, int64 *sum);
 static bool AdjustFractMicroseconds(double frac, int64 scale,
 									struct pg_itm_in *itm_in);
 static bool AdjustFractDays(double frac, int scale,
@@ -515,22 +514,6 @@ AppendTimestampSeconds(char *cp, struct pg_tm *tm, fsec_t fsec)
 	return AppendSeconds(cp, tm->tm_sec, fsec, MAX_TIMESTAMP_PRECISION, true);
 }
 
-
-/*
- * Add val * multiplier to *sum.
- * Returns true if successful, false on overflow.
- */
-static bool
-int64_multiply_add(int64 val, int64 multiplier, int64 *sum)
-{
-	int64		product;
-
-	if (pg_mul_s64_overflow(val, multiplier, &product) ||
-		pg_add_s64_overflow(*sum, product, sum))
-		return false;
-	return true;
-}
-
 /*
  * Multiply frac by scale (to produce microseconds) and add to itm_in->tm_usec.
  * Returns true if successful, false if itm_in overflows.
@@ -621,7 +604,7 @@ AdjustMicroseconds(int64 val, double fval, int64 scale,
 				   struct pg_itm_in *itm_in)
 {
 	/* Handle the integer part */
-	if (!int64_multiply_add(val, scale, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(val, scale, &itm_in->tm_usec))
 		return false;
 	/* Handle the float part */
 	return AdjustFractMicroseconds(fval, scale, itm_in);
@@ -2701,9 +2684,9 @@ DecodeTimeForInterval(char *str, int fmask, int range,
 		return dterr;
 
 	itm_in->tm_usec = itm.tm_usec;
-	if (!int64_multiply_add(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
-		!int64_multiply_add(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
+	if (pg_mul_add_s64_overflow(itm.tm_hour, USECS_PER_HOUR, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_min, USECS_PER_MINUTE, &itm_in->tm_usec) ||
+		pg_mul_add_s64_overflow(itm.tm_sec, USECS_PER_SEC, &itm_in->tm_usec))
 		return DTERR_FIELD_OVERFLOW;
 
 	return 0;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..81726c65f7 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -254,6 +254,19 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s64_overflow(int64 val, int64 multiplier, int64 *sum)
+{
+	int64		product;
+
+	return pg_mul_s64_overflow(val, multiplier, &product) ||
+		pg_add_s64_overflow(*sum, product, sum);
+}
+
 /*------------------------------------------------------------------------
  * Overflow routines for unsigned integers
  *------------------------------------------------------------------------
-- 
2.25.1

From 7e5ec988a6a300ff458a13b514920471433a1408 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 2/7] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 30 ++++++++++++++++++++------
 src/include/common/int.h               | 13 +++++++++++
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out |  7 ++++++
 src/test/regress/sql/interval.sql      |  5 +++++
 5 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..3ab9b6918e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1518,13 +1518,31 @@ make_interval(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
+	result->month = months;
+	if (pg_mul_add_s32_overflow(years, MONTHS_PER_YEAR, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->day = days;
+	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	result->time = (int64) secs;
+	if (pg_mul_add_s64_overflow(mins, ((int64) SECS_PER_MINUTE * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	if (pg_mul_add_s64_overflow(hours, ((int64) SECS_PER_HOUR * USECS_PER_SEC), &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 
 	PG_RETURN_INTERVAL_P(result);
 }
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 81726c65f7..48ef495551 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,19 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
 #endif
 }
 
+/*
+ * Add val * multiplier to *sum.
+ * Returns false if successful, true on overflow.
+ */
+static inline bool
+pg_mul_add_s32_overflow(int32 val, int32 multiplier, int32 *sum)
+{
+	int32		product;
+
+	return pg_mul_s32_overflow(val, multiplier, &product) ||
+		pg_add_s32_overflow(*sum, product, sum);
+}
+
 /*
  * INT64
  */
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e041b..96db07c3b4 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,13 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+ERROR:  interval out of range
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508d0..f328b8914d 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,11 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(1, 2147483647, 2147483647, 1, 1, 1, 9223372036854.7759);
+select make_interval(-1, -2147483648, -2147483648, -1, -1, -1, -9223372036854.7759);
+SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From c96cb360f5ce4a71f24f9dd12fbc10b9713f89b8 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 20 Sep 2023 15:41:00 +0530
Subject: [PATCH 5/7] Support infinite interval values in sum and avg window
 functions

Results of arithmetic operations involing both infinity and -infinity
intervals are undefined. Sliding window functions
accumulate and discard values as the window slides through the data.
Even if the data may have both infinities, none of windows may have both
of them together and thus produce definite results. Hence we can not use
normal operator functions to accumulate and discard values. Instead we
maintain a count of both infinities seen respectively in an aggregate
state and compute the aggregate for each window based on the accumulated
finite value and the counts of infinities, all of which are updated as
the window slides through the data.

Initial patch by Jian He, significantly edited by Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 407 ++++++++++++++++++---------
 src/include/catalog/pg_aggregate.dat |  23 +-
 src/include/catalog/pg_proc.dat      |  20 +-
 src/test/regress/expected/window.out |  62 ++++
 src/test/regress/sql/window.sql      |  43 +++
 src/tools/pgindent/typedefs.list     |   1 +
 6 files changed, 400 insertions(+), 156 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3100ad610f..21478c387c 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,6 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as Internal. It's
+ * a pointer to a IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of processed intervals */
+	Interval	sumX;			/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -82,6 +97,8 @@ static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
 static void interval_um_internal(Interval *interval, Interval *result);
+static void finite_interval_pl(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3447,34 +3464,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-	{
-		result->month = span1->month + span2->month;
-		/* overflow check copied from int4pl */
-		if (SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day + span2->day;
-		if (SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time + span2->time;
-		if (SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_pl(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3860,161 +3850,300 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function that needs to compute
+ * sum and count.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Function to add two finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * We handle non-finite intervals in different ways when accumulating intervals
+ * and adding two intervals respectively. But the addition of finite interval
+ * has same implementation in both these cases.
  */
+static void
+finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
-Datum
-interval_accum(PG_FUNCTION_ARGS)
+	result->month = span1->month + span2->month;
+	/* overflow check copied from int4pl */
+	if (SAMESIGN(span1->month, span2->month) &&
+		!SAMESIGN(result->month, span1->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = span1->day + span2->day;
+	if (SAMESIGN(span1->day, span2->day) &&
+		!SAMESIGN(result->day, span1->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->time = span1->time + span2->time;
+	if (SAMESIGN(span1->time, span2->time) &&
+		!SAMESIGN(result->time, span1->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	Interval	temp;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	memcpy(&temp, &state->sumX, sizeof(Interval));
+	finite_interval_pl(&state->sumX, &temp, newval);
+	state->N++;
+}
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+/*
+ * Transition function for interval aggregates.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/*
+ * Combine function for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_combine(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
 
-	Interval   *newsum;
-	ArrayType  *result;
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		state1 = makeIntervalAggState(fcinfo);
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		Interval	temp;
+
+		/* Accumulate interval values */
+		memcpy(&temp, &state1->sumX, sizeof(Interval));
+		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
+	}
+
+	PG_RETURN_POINTER(state1);
+}
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* Handle to be discarded finite value. */
+	if (state->N > 0)
+	{
+		Interval	temp;
+		Interval	neg_val;
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+		neg_val.day = -newval->day;
+		neg_val.month = -newval->month;
+		neg_val.time = -newval->time;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+		memcpy(&temp, &state->sumX, sizeof(Interval));
+		finite_interval_pl(&state->sumX, &temp, &neg_val);
+	}
+	else
+	{
+		/* All values discarded, reset the state */
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+	state->N--;
 }
 
+/*
+ * Generic inverse transition function for interval aggregates
+ */
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	double		N_datum;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = (double) state->N;
+	sumX = &state->sumX;
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
+										Float8GetDatum(N_datum)));
 }
 
+/* sum(interval) aggregate final function */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_sum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+	Interval   *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	result = (Interval *) palloc(sizeof(Interval));
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
-}
+	/* adding plus and minus interval infinities is not possible */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
 
+	memcpy(result, &state->sumX, sizeof(Interval));
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e2087d7be1 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,12 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9805bc6118..f8eca58ddf 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4914,17 +4914,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..45262924cd 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,68 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum 
+-----------+---------------+----------------
+ -infinity | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity
+ infinity  | infinity      | infinity
+ infinity  | infinity      | infinity
+           |               | infinity
+           |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..d00423946d 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,49 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f3d8a2a855..4df61a69ca 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1204,6 +1204,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.25.1

From bb51c8162c6ae84d94e3ab42de55fa6198aea2fe Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH 4/7] Introduce 'infinity' interval specification in
 DecodeInterval()

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Infinte interval specification i.e. "+infinity", "-infinity" or
"infinity" does not require anything other that one of the three
strings. Fix DecodeInterval() to disallow anything else.

"ago" may be used to revrse the sign of infinity specification like how
ago reverts the sign of finite intervals. But that is not as intuitive
as it is with finite intervals. Hence disallows "infinity ago" as well.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       | 24 ++++++++++++++++
 src/test/regress/expected/interval.out | 39 ++++++++++++++++++++++++++
 src/test/regress/sql/interval.sql      | 14 +++++++++
 3 files changed, 77 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 5fed7e3dd1..b25bd6a551 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3254,6 +3254,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3582,6 +3585,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * infinity can not be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but that signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index a4630d17ef..d61b07f38e 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2244,3 +2244,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 023cf3761a..183ddfaf31 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -735,3 +735,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
-- 
2.25.1

From 12fbd8b15c963e1e69294ade4f6f5af6ef7b27c5 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 15:34:33 +0530
Subject: [PATCH 6/7] Use integer overflow checking routines to add and
 subtract finite intervals

Use pg_add/sub_s32/64_overflow() routines in finite_interval_pl() and
finite_interval_mi() instead of adding overflow checks in those
functions.

Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c      | 121 +++++++++++--------------
 src/test/regress/expected/interval.out |  11 +++
 src/test/regress/expected/window.out   |  54 ++++-------
 src/test/regress/sql/interval.sql      |   3 +
 src/test/regress/sql/window.sql        |  22 ++---
 5 files changed, 95 insertions(+), 116 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 21478c387c..17415cc4bd 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -99,6 +99,8 @@ static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 static void interval_um_internal(Interval *interval, Interval *result);
 static void finite_interval_pl(Interval *result, Interval *span1,
 							   Interval *span2);
+static void finite_interval_mi(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3506,34 +3508,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-	{
-		result->month = span1->month - span2->month;
-		/* overflow check copied from int4mi */
-		if (!SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day - span2->day;
-		if (!SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time - span2->time;
-		if (!SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_mi(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3873,11 +3848,18 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Function to add two finite intervals.
+ * Functions to add or subtract two finite intervals.
+ *
+ * We handle non-finite intervals in different ways when accumulating/discarding
+ * intervals and in actual mathematical operations respectively. But the
+ * addition or subtraction of finite intervals have same implementation
+ * respectively in both these cases.
+ *
+ * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
+ * to pass either of span1 or span2 as a result pointer. In such a case result
+ * will overwrite the given value.
  *
- * We handle non-finite intervals in different ways when accumulating intervals
- * and adding two intervals respectively. But the addition of finite interval
- * has same implementation in both these cases.
+ * If the result is not a valid interval, the function throws an error.
  */
 static void
 finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
@@ -3885,24 +3867,44 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
@@ -3919,9 +3921,6 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-
-	Interval	temp;
-
 	/* Count -infinity inputs separately from all else */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
@@ -3936,8 +3935,7 @@ do_interval_accum(IntervalAggState *state, Interval *newval)
 		return;
 	}
 
-	memcpy(&temp, &state->sumX, sizeof(Interval));
-	finite_interval_pl(&state->sumX, &temp, newval);
+	finite_interval_pl(&state->sumX, &state->sumX, newval);
 	state->N++;
 }
 
@@ -3963,6 +3961,9 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 
 /*
  * Combine function for interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in the
+ * first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3976,9 +3977,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	if (state2 == NULL)
 		PG_RETURN_POINTER(state1);
 
-	/* manually copy all fields from state2 to state1 */
 	if (state1 == NULL)
 	{
+		/* manually copy all fields from state2 to state1 */
 		state1 = makeIntervalAggState(fcinfo);
 
 		state1->N = state2->N;
@@ -3996,14 +3997,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	state1->pInfcount += state2->pInfcount;
 	state1->nInfcount += state2->nInfcount;
 
+	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-	{
-		Interval	temp;
-
-		/* Accumulate interval values */
-		memcpy(&temp, &state1->sumX, sizeof(Interval));
-		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
-	}
+		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4029,24 +4025,15 @@ do_interval_discard(IntervalAggState *state, Interval *newval)
 	}
 
 	/* Handle to be discarded finite value. */
+	state->N--;
 	if (state->N > 0)
-	{
-		Interval	temp;
-		Interval	neg_val;
-
-		neg_val.day = -newval->day;
-		neg_val.month = -newval->month;
-		neg_val.time = -newval->time;
-
-		memcpy(&temp, &state->sumX, sizeof(Interval));
-		finite_interval_pl(&state->sumX, &temp, &neg_val);
-	}
+		finite_interval_mi(&state->sumX, &state->sumX, newval);
 	else
 	{
 		/* All values discarded, reset the state */
+		Assert(state->N == 0);
 		memset(&state->sumX, 0, sizeof(state->sumX));
 	}
-	state->N--;
 }
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index d61b07f38e..c5587fc903 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -347,6 +347,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 45262924cd..63f36e069e 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,51 +4375,37 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-     x     | curr_next_avg | prev1_curr_sum 
------------+---------------+----------------
- -infinity | -infinity     | -infinity
- @ 6 days  | infinity      | -infinity
- infinity  | infinity      | infinity
- infinity  | infinity      | infinity
-           |               | infinity
-           |               | 
-(6 rows)
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
------------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
-           | infinity          | infinity      |                   |                | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
- @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
-           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
- -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
-(7 rows)
+                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
+----------------------------------------------+-------------------+-------------------+---------------+----------------
+                                              | infinity          |                   | infinity      | 
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
 
 --should fail.
 SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 183ddfaf31..e31c5c3d98 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -99,6 +99,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index d00423946d..6dd9885949 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,28 +1591,20 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
-- 
2.25.1

From 9442b707b6aec49da063ae1714716325cef826dd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 3/7] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   4 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 707 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1546 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..557b81cae8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,12 +2320,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..7786853743 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 48fc0d5942..5fed7e3dd1 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3557,6 +3557,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef97..e9e85503f8 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3ab9b6918e..3100ad610f 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1523,6 +1545,7 @@ make_interval(PG_FUNCTION_ARGS)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+
 	result->day = days;
 	if (pg_mul_add_s32_overflow(weeks, DAYS_PER_WEEK, &result->day))
 		ereport(ERROR,
@@ -1544,6 +1567,11 @@ make_interval(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -1561,6 +1589,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2039,6 +2078,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2056,6 +2097,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2089,7 +2132,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2220,6 +2265,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2715,46 +2783,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2784,6 +2877,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2836,6 +2932,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2859,6 +2960,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2876,6 +2980,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2897,6 +3006,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2915,6 +3027,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2935,7 +3052,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3014,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3043,7 +3181,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3133,9 +3294,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3186,6 +3345,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3193,23 +3377,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3253,27 +3421,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3287,27 +3488,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3332,6 +3568,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3392,6 +3671,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3423,6 +3707,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3444,6 +3751,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3727,8 +4039,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3847,8 +4186,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3973,6 +4339,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4156,6 +4527,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4394,6 +4770,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4738,7 +5120,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5012,7 +5394,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5252,6 +5634,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5276,6 +5711,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5518,6 +5981,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5748,6 +6218,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5814,6 +6291,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5896,6 +6378,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 96db07c3b4..a4630d17ef 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1596,31 +1649,31 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1699,19 +1752,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1785,7 +1840,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1794,6 +1851,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index f328b8914d..023cf3761a 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -518,13 +525,13 @@ SELECT make_interval(0, 0, 0, 0, 0, 0, 9223372036854.776000);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -588,6 +595,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From d7e41a0b6dc3bc7f1f514f1662281b75a29bddf0 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 16:52:30 +0530
Subject: [PATCH 7/7] Implement serialization functions for interval aggregate
 state

Now that interval aggregates use transition state which of date type Internal,
parallel aggregates require these separate functions.

Jian He and Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 86 +++++++++++++++++++++++++++-
 src/include/catalog/pg_aggregate.dat |  4 ++
 src/include/catalog/pg_proc.dat      |  6 ++
 3 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 17415cc4bd..cffb5d4c61 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3825,8 +3825,12 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * Prepare state data for an interval aggregate function that needs to compute
- * sum and count.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
  */
 static IntervalAggState *
 makeIntervalAggState(FunctionCallInfo fcinfo)
@@ -4004,6 +4008,84 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_serialize(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
+
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	/* TODO: Handle NULL inputs? */
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+	pq_begintypsend(&buf);
+	/* N */
+	pq_sendint64(&buf, state->N);
+	/* Finite interval value */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
+	result = pq_endtypsend(&buf);
+	PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_deserialize(PG_FUNCTION_ARGS)
+{
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	sstate = PG_GETARG_BYTEA_PP(0);
+
+	/*
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
+	 */
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
+
+	/* Interval struct elements, one by one. */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
+	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+	pfree(buf.data);
+
+	PG_RETURN_POINTER(result);
+}
+
 /*
  * Remove the given interval value from the aggregated state.
  */
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index e2087d7be1..0e62c3f7a6 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -45,6 +45,8 @@
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
 { aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
@@ -75,6 +77,8 @@
   aggtranstype => 'money', aggmtranstype => 'money' },
 { aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8eca58ddf..34da5f3687 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4925,6 +4925,12 @@
   proname => 'interval_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
   prosrc => 'interval_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
-- 
2.25.1

From 102d37b219254f204c2af33b616ad8b90e11febb Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH v25 1/7] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 39 ++++++++++++++++++--------
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out | 27 ++++++++++++++++++
 src/test/regress/sql/interval.sql      | 15 ++++++++++
 4 files changed, 71 insertions(+), 11 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..7ddf64ad2e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1509,24 +1509,41 @@ make_interval(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	/*
-	 * Reject out-of-range inputs.  We really ought to check the integer
-	 * inputs as well, but it's not entirely clear what limits to apply.
+	 * Reject out-of-range inputs.  We reject any input values that cause
+	 * integer overflow of the corresponding interval fields.
 	 */
 	if (isinf(secs) || isnan(secs))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		goto out_of_range;
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	/* years and months -> months */
+	if (pg_mul_s32_overflow(years, MONTHS_PER_YEAR, &result->month) ||
+		pg_add_s32_overflow(result->month, months, &result->month))
+		goto out_of_range;
+
+	/* weeks and days -> days */
+	if (pg_mul_s32_overflow(weeks, DAYS_PER_WEEK, &result->day) ||
+		pg_add_s32_overflow(result->day, days, &result->day))
+		goto out_of_range;
+
+	/* hours and mins -> usecs (cannot overflow 64-bit) */
+	result->time = hours * USECS_PER_HOUR + mins * USECS_PER_MINUTE;
+
+	/* secs -> usecs */
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs) ||
+		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
+		goto out_of_range;
 
 	PG_RETURN_INTERVAL_P(result);
+
+out_of_range:
+	ereport(ERROR,
+			errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+			errmsg("interval out of range"));
+
+	PG_RETURN_NULL();			/* keep compiler quiet */
 }
 
 /* EncodeSpecialTimestamp()
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e041b..75d19d6594 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,33 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(years := 178956971);
+ERROR:  interval out of range
+select make_interval(years := -178956971);
+ERROR:  interval out of range
+select make_interval(years := 1, months := 2147483647);
+ERROR:  interval out of range
+select make_interval(years := -1, months := -2147483648);
+ERROR:  interval out of range
+select make_interval(weeks := 306783379);
+ERROR:  interval out of range
+select make_interval(weeks := -306783379);
+ERROR:  interval out of range
+select make_interval(weeks := 1, days := 2147483647);
+ERROR:  interval out of range
+select make_interval(weeks := -1, days := -2147483648);
+ERROR:  interval out of range
+select make_interval(secs := 1e308);
+ERROR:  value out of range: overflow
+select make_interval(secs := 1e18);
+ERROR:  interval out of range
+select make_interval(secs := -1e18);
+ERROR:  interval out of range
+select make_interval(mins := 1, secs := 9223372036800.0);
+ERROR:  interval out of range
+select make_interval(mins := -1, secs := -9223372036800.0);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508d0..a0a373f08b 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,21 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(years := 178956971);
+select make_interval(years := -178956971);
+select make_interval(years := 1, months := 2147483647);
+select make_interval(years := -1, months := -2147483648);
+select make_interval(weeks := 306783379);
+select make_interval(weeks := -306783379);
+select make_interval(weeks := 1, days := 2147483647);
+select make_interval(weeks := -1, days := -2147483648);
+select make_interval(secs := 1e308);
+select make_interval(secs := 1e18);
+select make_interval(secs := -1e18);
+select make_interval(mins := 1, secs := 9223372036800.0);
+select make_interval(mins := -1, secs := -9223372036800.0);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.35.3

From bcd47fd63d1a602518864f0ac66b2e07806c3854 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 15:34:33 +0530
Subject: [PATCH v25 5/7] Use integer overflow checking routines to add and
 subtract finite intervals

Use pg_add/sub_s32/64_overflow() routines in finite_interval_pl() and
finite_interval_mi() instead of adding overflow checks in those
functions.

Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c      | 121 +++++++++++--------------
 src/test/regress/expected/interval.out |  11 +++
 src/test/regress/expected/window.out   |  54 ++++-------
 src/test/regress/sql/interval.sql      |   3 +
 src/test/regress/sql/window.sql        |  22 ++---
 5 files changed, 95 insertions(+), 116 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 50fb793c13..8c1b0a774b 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -99,6 +99,8 @@ static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 static void interval_um_internal(Interval *interval, Interval *result);
 static void finite_interval_pl(Interval *result, Interval *span1,
 							   Interval *span2);
+static void finite_interval_mi(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3502,34 +3504,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-	{
-		result->month = span1->month - span2->month;
-		/* overflow check copied from int4mi */
-		if (!SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day - span2->day;
-		if (!SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time - span2->time;
-		if (!SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_mi(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3869,11 +3844,18 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Function to add two finite intervals.
+ * Functions to add or subtract two finite intervals.
+ *
+ * We handle non-finite intervals in different ways when accumulating/discarding
+ * intervals and in actual mathematical operations respectively. But the
+ * addition or subtraction of finite intervals have same implementation
+ * respectively in both these cases.
+ *
+ * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
+ * to pass either of span1 or span2 as a result pointer. In such a case result
+ * will overwrite the given value.
  *
- * We handle non-finite intervals in different ways when accumulating intervals
- * and adding two intervals respectively. But the addition of finite interval
- * has same implementation in both these cases.
+ * If the result is not a valid interval, the function throws an error.
  */
 static void
 finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
@@ -3881,24 +3863,44 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
@@ -3915,9 +3917,6 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-
-	Interval	temp;
-
 	/* Count -infinity inputs separately from all else */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
@@ -3932,8 +3931,7 @@ do_interval_accum(IntervalAggState *state, Interval *newval)
 		return;
 	}
 
-	memcpy(&temp, &state->sumX, sizeof(Interval));
-	finite_interval_pl(&state->sumX, &temp, newval);
+	finite_interval_pl(&state->sumX, &state->sumX, newval);
 	state->N++;
 }
 
@@ -3959,6 +3957,9 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 
 /*
  * Combine function for interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in the
+ * first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3972,9 +3973,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	if (state2 == NULL)
 		PG_RETURN_POINTER(state1);
 
-	/* manually copy all fields from state2 to state1 */
 	if (state1 == NULL)
 	{
+		/* manually copy all fields from state2 to state1 */
 		state1 = makeIntervalAggState(fcinfo);
 
 		state1->N = state2->N;
@@ -3992,14 +3993,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	state1->pInfcount += state2->pInfcount;
 	state1->nInfcount += state2->nInfcount;
 
+	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-	{
-		Interval	temp;
-
-		/* Accumulate interval values */
-		memcpy(&temp, &state1->sumX, sizeof(Interval));
-		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
-	}
+		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4025,24 +4021,15 @@ do_interval_discard(IntervalAggState *state, Interval *newval)
 	}
 
 	/* Handle to be discarded finite value. */
+	state->N--;
 	if (state->N > 0)
-	{
-		Interval	temp;
-		Interval	neg_val;
-
-		neg_val.day = -newval->day;
-		neg_val.month = -newval->month;
-		neg_val.time = -newval->time;
-
-		memcpy(&temp, &state->sumX, sizeof(Interval));
-		finite_interval_pl(&state->sumX, &temp, &neg_val);
-	}
+		finite_interval_mi(&state->sumX, &state->sumX, newval);
 	else
 	{
 		/* All values discarded, reset the state */
+		Assert(state->N == 0);
 		memset(&state->sumX, 0, sizeof(state->sumX));
 	}
-	state->N--;
 }
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 135d683285..8bd72f60b0 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -347,6 +347,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 45262924cd..63f36e069e 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,51 +4375,37 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-     x     | curr_next_avg | prev1_curr_sum 
------------+---------------+----------------
- -infinity | -infinity     | -infinity
- @ 6 days  | infinity      | -infinity
- infinity  | infinity      | infinity
- infinity  | infinity      | infinity
-           |               | infinity
-           |               | 
-(6 rows)
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
------------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
-           | infinity          | infinity      |                   |                | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
- @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
-           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
- -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
-(7 rows)
+                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
+----------------------------------------------+-------------------+-------------------+---------------+----------------
+                                              | infinity          |                   | infinity      | 
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
 
 --should fail.
 SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 912803a1b0..414c12be1c 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -99,6 +99,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index d00423946d..6dd9885949 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,28 +1591,20 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
-- 
2.35.3

From 69d8e9779b2016c4a96262a24c22e10eccdfea0c Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH v25 3/7] Introduce 'infinity' interval specification in
 DecodeInterval()

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Infinte interval specification i.e. "+infinity", "-infinity" or
"infinity" does not require anything other that one of the three
strings. Fix DecodeInterval() to disallow anything else.

"ago" may be used to revrse the sign of infinity specification like how
ago reverts the sign of finite intervals. But that is not as intuitive
as it is with finite intervals. Hence disallows "infinity ago" as well.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       | 24 ++++++++++++++++
 src/test/regress/expected/interval.out | 39 ++++++++++++++++++++++++++
 src/test/regress/sql/interval.sql      | 14 +++++++++
 3 files changed, 77 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index ea2bc65f50..73dadb747c 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3599,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * infinity can not be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but that signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 5011fc4815..135d683285 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2264,3 +2264,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 590e1000bd..912803a1b0 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -745,3 +745,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
-- 
2.35.3

From 1d2314afbbfb551fa841eee95861ffdfd81bfda5 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 20 Sep 2023 15:41:00 +0530
Subject: [PATCH v25 4/7] Support infinite interval values in sum and avg
 window functions

Results of arithmetic operations involing both infinity and -infinity
intervals are undefined. Sliding window functions
accumulate and discard values as the window slides through the data.
Even if the data may have both infinities, none of windows may have both
of them together and thus produce definite results. Hence we can not use
normal operator functions to accumulate and discard values. Instead we
maintain a count of both infinities seen respectively in an aggregate
state and compute the aggregate for each window based on the accumulated
finite value and the counts of infinities, all of which are updated as
the window slides through the data.

Initial patch by Jian He, significantly edited by Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 407 ++++++++++++++++++---------
 src/include/catalog/pg_aggregate.dat |  23 +-
 src/include/catalog/pg_proc.dat      |  20 +-
 src/test/regress/expected/window.out |  62 ++++
 src/test/regress/sql/window.sql      |  43 +++
 src/tools/pgindent/typedefs.list     |   1 +
 6 files changed, 400 insertions(+), 156 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index c52bdb68da..50fb793c13 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,6 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as Internal. It's
+ * a pointer to a IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of processed intervals */
+	Interval	sumX;			/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -82,6 +97,8 @@ static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
 static void interval_um_internal(Interval *interval, Interval *result);
+static void finite_interval_pl(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3443,34 +3460,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-	{
-		result->month = span1->month + span2->month;
-		/* overflow check copied from int4pl */
-		if (SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day + span2->day;
-		if (SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time + span2->time;
-		if (SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_pl(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3856,161 +3846,300 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function that needs to compute
+ * sum and count.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Function to add two finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * We handle non-finite intervals in different ways when accumulating intervals
+ * and adding two intervals respectively. But the addition of finite interval
+ * has same implementation in both these cases.
  */
+static void
+finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
-Datum
-interval_accum(PG_FUNCTION_ARGS)
+	result->month = span1->month + span2->month;
+	/* overflow check copied from int4pl */
+	if (SAMESIGN(span1->month, span2->month) &&
+		!SAMESIGN(result->month, span1->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = span1->day + span2->day;
+	if (SAMESIGN(span1->day, span2->day) &&
+		!SAMESIGN(result->day, span1->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->time = span1->time + span2->time;
+	if (SAMESIGN(span1->time, span2->time) &&
+		!SAMESIGN(result->time, span1->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	Interval	temp;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	memcpy(&temp, &state->sumX, sizeof(Interval));
+	finite_interval_pl(&state->sumX, &temp, newval);
+	state->N++;
+}
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+/*
+ * Transition function for interval aggregates.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/*
+ * Combine function for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_combine(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
 
-	Interval   *newsum;
-	ArrayType  *result;
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		state1 = makeIntervalAggState(fcinfo);
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		Interval	temp;
+
+		/* Accumulate interval values */
+		memcpy(&temp, &state1->sumX, sizeof(Interval));
+		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
+	}
+
+	PG_RETURN_POINTER(state1);
+}
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* Handle to be discarded finite value. */
+	if (state->N > 0)
+	{
+		Interval	temp;
+		Interval	neg_val;
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+		neg_val.day = -newval->day;
+		neg_val.month = -newval->month;
+		neg_val.time = -newval->time;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+		memcpy(&temp, &state->sumX, sizeof(Interval));
+		finite_interval_pl(&state->sumX, &temp, &neg_val);
+	}
+	else
+	{
+		/* All values discarded, reset the state */
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+	state->N--;
 }
 
+/*
+ * Generic inverse transition function for interval aggregates
+ */
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	double		N_datum;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = (double) state->N;
+	sumX = &state->sumX;
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
+										Float8GetDatum(N_datum)));
 }
 
+/* sum(interval) aggregate final function */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_sum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+	Interval   *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	result = (Interval *) palloc(sizeof(Interval));
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
-}
+	/* adding plus and minus interval infinities is not possible */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
 
+	memcpy(result, &state->sumX, sizeof(Interval));
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e2087d7be1 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,12 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f0b7b9cbd8..52ef90ba6c 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4914,17 +4914,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..45262924cd 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,68 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum 
+-----------+---------------+----------------
+ -infinity | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity
+ infinity  | infinity      | infinity
+ infinity  | infinity      | infinity
+           |               | infinity
+           |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..d00423946d 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,49 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 8de90c4958..5a81b42fd6 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1204,6 +1204,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3

From 06386aebc49feda9123098400c11d0dd78dee998 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH v25 2/7] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   4 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 704 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1543 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5d23765705..123d8207f8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,12 +2321,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..7786853743 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..ea2bc65f50 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3574,6 +3574,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef97..e9e85503f8 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 7ddf64ad2e..c52bdb68da 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1558,9 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1585,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2038,6 +2074,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2055,6 +2093,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2088,7 +2128,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2219,6 +2261,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2714,46 +2779,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2783,6 +2873,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2835,6 +2928,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2858,6 +2956,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2875,6 +2976,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2896,6 +3002,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2914,6 +3023,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2934,7 +3048,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3150,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3177,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3290,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3341,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3373,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3417,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3484,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3564,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3667,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3703,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3747,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3726,8 +4035,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4182,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4335,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4523,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4766,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5116,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5390,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5630,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5707,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +5977,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6214,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5813,6 +6287,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5895,6 +6374,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..5011fc4815 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1669,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1772,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1860,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1871,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..590e1000bd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -528,13 +535,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +605,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.35.3

From 2dd11e05c325f191e3a78a1f6bd4eafa916574e3 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 16:52:30 +0530
Subject: [PATCH v25 6/7] Implement serialization functions for interval
 aggregate state

Now that interval aggregates use transition state which of date type Internal,
parallel aggregates require these separate functions.

Jian He and Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 86 +++++++++++++++++++++++++++-
 src/include/catalog/pg_aggregate.dat |  4 ++
 src/include/catalog/pg_proc.dat      |  6 ++
 3 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 8c1b0a774b..bf02ddb92d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3821,8 +3821,12 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * Prepare state data for an interval aggregate function that needs to compute
- * sum and count.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
  */
 static IntervalAggState *
 makeIntervalAggState(FunctionCallInfo fcinfo)
@@ -4000,6 +4004,84 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_serialize(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
+
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	/* TODO: Handle NULL inputs? */
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+	pq_begintypsend(&buf);
+	/* N */
+	pq_sendint64(&buf, state->N);
+	/* Finite interval value */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
+	result = pq_endtypsend(&buf);
+	PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_deserialize(PG_FUNCTION_ARGS)
+{
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	sstate = PG_GETARG_BYTEA_PP(0);
+
+	/*
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
+	 */
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
+
+	/* Interval struct elements, one by one. */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
+	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+	pfree(buf.data);
+
+	PG_RETURN_POINTER(result);
+}
+
 /*
  * Remove the given interval value from the aggregated state.
  */
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index e2087d7be1..0e62c3f7a6 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -45,6 +45,8 @@
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
 { aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
@@ -75,6 +77,8 @@
   aggtranstype => 'money', aggmtranstype => 'money' },
 { aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 52ef90ba6c..449c1dae82 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4925,6 +4925,12 @@
   proname => 'interval_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
   prosrc => 'interval_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
-- 
2.35.3

From 3351dac79dbdfa108eafa1aae4c54acd905e6510 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Thu, 28 Sep 2023 14:54:02 +0100
Subject: [PATCH v25 7/7] Code review of infinite interval support.

---
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  27 +-
 src/backend/utils/adt/datetime.c          |   4 +-
 src/backend/utils/adt/selfuncs.c          |  16 +-
 src/backend/utils/adt/timestamp.c         | 366 +++++++++----------
 src/include/catalog/pg_aggregate.dat      |  11 +-
 src/include/catalog/pg_proc.dat           |   6 +-
 src/include/datatype/timestamp.h          |  24 +-
 src/include/utils/timestamp.h             |   3 -
 src/test/regress/expected/interval.out    | 375 ++++++++------------
 src/test/regress/expected/timestamp.out   |   8 +-
 src/test/regress/expected/timestamptz.out |   8 +-
 src/test/regress/expected/window.out      | 406 +++++++++++++++++++---
 src/test/regress/sql/interval.sql         | 131 +++----
 src/test/regress/sql/window.sql           |  93 ++++-
 15 files changed, 912 insertions(+), 571 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7786853743..2fd9db9afa 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10435,7 +10435,10 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
      <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
-     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index f2107dd967..ef06474ac3 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2050,8 +2051,6 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
-	Assert(!INTERVAL_NOT_FINITE(result));
-
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2116,7 +2115,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2126,13 +2126,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2666,7 +2667,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2676,13 +2678,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 73dadb747c..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3613,9 +3613,9 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 							return DTERR_BAD_FORMAT;
 
 						/*
-						 * infinity can not be followed by anything else. We
+						 * Infinity cannot be followed by anything else. We
 						 * could allow "ago" to reverse the sign of infinity
-						 * but that signed infinity is more intuitive.
+						 * but using signed infinity is more intuitive.
 						 */
 						if (i != nf - 1)
 							return DTERR_BAD_FORMAT;
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 6e87173846..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,7 +4795,21 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
+			{
+				Interval   *interval = DatumGetIntervalP(value);
+
+				/*
+				 * Convert the month part of Interval to days using assumed
+				 * average month length of 365.25/12.0 days.  Not too
+				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
+				 */
+				return interval->time + interval->day * (double) USECS_PER_DAY +
+					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+			}
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index bf02ddb92d..c8e1fb9f9d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,7 +18,6 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
-#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -74,16 +73,16 @@ typedef struct
 } generate_series_timestamptz_fctx;
 
 /*
- * The transition datatype for interval aggregates is declared as Internal. It's
- * a pointer to a IntervalAggState allocated in the aggregate context.
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
  */
 typedef struct IntervalAggState
 {
-	int64		N;				/* count of processed intervals */
-	Interval	sumX;			/* sum of processed intervals */
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
 	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
-	int64		pInfcount;		/* count of +Inf values */
-	int64		nInfcount;		/* count of -Inf values */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
 } IntervalAggState;
 
 #define IA_TOTAL_COUNT(ia) \
@@ -96,11 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
-static void interval_um_internal(Interval *interval, Interval *result);
-static void finite_interval_pl(Interval *result, Interval *span1,
-							   Interval *span2);
-static void finite_interval_mi(Interval *result, Interval *span1,
-							   Interval *span2);
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -1604,8 +1604,8 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
-void
-EncodeSpecialInterval(Interval *interval, char *str)
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
 {
 	if (INTERVAL_IS_NOBEGIN(interval))
 		strcpy(str, EARLY);
@@ -2101,6 +2101,13 @@ itm2interval(struct pg_itm *itm, Interval *span)
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2112,8 +2119,6 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
-	if (INTERVAL_NOT_FINITE(span))
-		return -1;
 	return 0;
 }
 
@@ -2280,29 +2285,6 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
-double
-interval2timestamp_no_overflow(Interval *interval)
-{
-	double		result;
-
-	if (INTERVAL_IS_NOBEGIN(interval))
-		result = -DBL_MAX;
-	else if (INTERVAL_IS_NOEND(interval))
-		result = DBL_MAX;
-	else
-	{
-		/*
-		 * Convert the month part of Interval to days using assumed average
-		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
-		 * good enough for our purposes.
-		 */
-		return interval->time + interval->day * (double) USECS_PER_DAY +
-			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-	}
-
-	return result;
-}
-
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2526,6 +2508,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2801,14 +2792,14 @@ timestamp_mi(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -2817,7 +2808,7 @@ timestamp_mi(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -3068,16 +3059,16 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Timestamp	result;
 
 	/*
-	 * Adding two infinites with the same sign results in an infinite
-	 * timestamp with the same sign. Adding two infintes with different signs
-	 * results in an error.
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span))
 	{
 		if (TIMESTAMP_IS_NOEND(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOBEGIN(result);
 	}
@@ -3086,7 +3077,7 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOBEGIN(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOEND(result);
 	}
@@ -3197,16 +3188,16 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	int			tz;
 
 	/*
-	 * Adding two infinites with the same sign results in an infinite
-	 * timestamp with the same sign. Adding two infintes with different signs
-	 * results in an error.
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span))
 	{
 		if (TIMESTAMP_IS_NOEND(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOBEGIN(result);
 	}
@@ -3215,7 +3206,7 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 		if (TIMESTAMP_IS_NOBEGIN(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOEND(result);
 	}
@@ -3362,16 +3353,12 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 
 /* Negates the given interval */
 static void
-interval_um_internal(Interval *interval, Interval *result)
+interval_um_internal(const Interval *interval, Interval *result)
 {
 	if (INTERVAL_IS_NOBEGIN(interval))
 		INTERVAL_NOEND(result);
 	else if (INTERVAL_IS_NOEND(interval))
 		INTERVAL_NOBEGIN(result);
-	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
 	else
 	{
 		result->time = -interval->time;
@@ -3438,8 +3425,8 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	/*
 	 * Adding two infinite intervals with the same signs results in an
-	 * infinite interval with the same sign. Adding two infinte intervals with
-	 * different signs results in an error.
+	 * infinite interval with the same sign. Adding two infinite intervals
+	 * with different signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span1))
 	{
@@ -3462,7 +3449,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-		finite_interval_pl(result, span1, span2);
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3479,7 +3466,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite intervals with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte intervals with the same sign results in an error.
+	 * two infinite intervals with the same sign results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span1))
 	{
@@ -3504,7 +3491,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-		finite_interval_mi(result, span1, span2);
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3552,13 +3539,11 @@ interval_mul(PG_FUNCTION_ARGS)
 	}
 	else if (isinf(factor))
 	{
-		Interval	zero;
 		int			factor_sign,
 					result_sign;
 
 		factor_sign = factor >= 0.0 ? 1 : -1;
-		memset(&zero, 0, sizeof(zero));
-		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+		result_sign = interval_sign(span) * factor_sign;
 
 		if (result_sign == 0)
 			ereport(ERROR,
@@ -3740,11 +3725,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3767,11 +3762,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3798,11 +3803,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3848,21 +3863,13 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Functions to add or subtract two finite intervals.
+ * Functions to add or subtract finite intervals.
  *
- * We handle non-finite intervals in different ways when accumulating/discarding
- * intervals and in actual mathematical operations respectively. But the
- * addition or subtraction of finite intervals have same implementation
- * respectively in both these cases.
- *
- * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
- * to pass either of span1 or span2 as a result pointer. In such a case result
- * will overwrite the given value.
- *
- * If the result is not a valid interval, the function throws an error.
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
  */
 static void
-finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
 {
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
@@ -3889,7 +3896,7 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 }
 
 static void
-finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
 {
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
@@ -3921,26 +3928,56 @@ finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	/* Count -infinity inputs separately from all else */
+	/* Infinite inputs are counted separately, and do not affect "N" */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
 		state->nInfcount++;
 		return;
 	}
 
-	/* Count infinity inputs separately from all else */
 	if (INTERVAL_IS_NOEND(newval))
 	{
 		state->pInfcount++;
 		return;
 	}
 
-	finite_interval_pl(&state->sumX, &state->sumX, newval);
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
 	state->N++;
 }
 
 /*
- * Transition function for interval aggregates.
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle to be discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
  */
 Datum
 interval_avg_accum(PG_FUNCTION_ARGS)
@@ -3960,10 +3997,10 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 }
 
 /*
- * Combine function for interval aggregates.
+ * Combine function for sum() and avg() interval aggregates.
  *
- * Combine the given internal aggregate states and place the combination in the
- * first argument.
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3999,7 +4036,7 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 
 	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4019,20 +4056,26 @@ interval_avg_serialize(PG_FUNCTION_ARGS)
 	if (!AggCheckCallContext(fcinfo, NULL))
 		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	/* TODO: Handle NULL inputs? */
 	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+
 	pq_begintypsend(&buf);
+
 	/* N */
 	pq_sendint64(&buf, state->N);
-	/* Finite interval value */
+
+	/* sumX */
 	pq_sendint64(&buf, state->sumX.time);
 	pq_sendint32(&buf, state->sumX.day);
 	pq_sendint32(&buf, state->sumX.month);
+
 	/* pInfcount */
 	pq_sendint64(&buf, state->pInfcount);
+
 	/* nInfcount */
 	pq_sendint64(&buf, state->nInfcount);
+
 	result = pq_endtypsend(&buf);
+
 	PG_RETURN_BYTEA_P(result);
 }
 
@@ -4065,10 +4108,10 @@ interval_avg_deserialize(PG_FUNCTION_ARGS)
 	/* N */
 	result->N = pq_getmsgint64(&buf);
 
-	/* Interval struct elements, one by one. */
+	/* sumX */
 	result->sumX.time = pq_getmsgint64(&buf);
-	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
-	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
 
 	/* pInfcount */
 	result->pInfcount = pq_getmsgint64(&buf);
@@ -4083,42 +4126,10 @@ interval_avg_deserialize(PG_FUNCTION_ARGS)
 }
 
 /*
- * Remove the given interval value from the aggregated state.
- */
-static void
-do_interval_discard(IntervalAggState *state, Interval *newval)
-{
-	/* Count -infinity inputs separately from all else */
-	if (INTERVAL_IS_NOBEGIN(newval))
-	{
-		state->nInfcount--;
-		return;
-	}
-
-	/* Count infinity inputs separately from all else */
-	if (INTERVAL_IS_NOEND(newval))
-	{
-		state->pInfcount--;
-		return;
-	}
-
-	/* Handle to be discarded finite value. */
-	state->N--;
-	if (state->N > 0)
-		finite_interval_mi(&state->sumX, &state->sumX, newval);
-	else
-	{
-		/* All values discarded, reset the state */
-		Assert(state->N == 0);
-		memset(&state->sumX, 0, sizeof(state->sumX));
-	}
-}
-
-/*
- * Generic inverse transition function for interval aggregates
+ * Inverse transition function for sum() and avg() interval aggregates.
  */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
 	IntervalAggState *state;
 
@@ -4126,7 +4137,7 @@ interval_accum_inv(PG_FUNCTION_ARGS)
 
 	/* Should not get here with no state */
 	if (state == NULL)
-		elog(ERROR, "interval_accum_inv called with NULL state");
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
 
 	if (!PG_ARGISNULL(1))
 		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
@@ -4139,38 +4150,39 @@ Datum
 interval_avg(PG_FUNCTION_ARGS)
 {
 	IntervalAggState *state;
-	double		N_datum;
-	Interval   *sumX;
 
-	sumX = (Interval *) palloc(sizeof(Interval));
 	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
+	/* If there were no non-null inputs, return NULL */
 	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	/* adding plus and minus infinities gives error */
-	if (state->pInfcount > 0 && state->nInfcount > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range.")));
-
-	if (state->pInfcount > 0)
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
 	{
-		INTERVAL_NOEND(sumX);
-		PG_RETURN_INTERVAL_P(sumX);
-	}
+		Interval   *result;
 
-	if (state->nInfcount > 0)
-	{
-		INTERVAL_NOBEGIN(sumX);
-		PG_RETURN_INTERVAL_P(sumX);
-	}
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
 
-	N_datum = (double) state->N;
-	sumX = &state->sumX;
+		PG_RETURN_INTERVAL_P(result);
+	}
 
-	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
-										Float8GetDatum(N_datum)));
+	return DirectFunctionCall2(interval_div,
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
 /* sum(interval) aggregate final function */
@@ -4180,33 +4192,31 @@ interval_sum(PG_FUNCTION_ARGS)
 	IntervalAggState *state;
 	Interval   *result;
 
-	result = (Interval *) palloc(sizeof(Interval));
-
 	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
 	/* If there were no non-null inputs, return NULL */
 	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	/* adding plus and minus interval infinities is not possible */
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
 	if (state->pInfcount > 0 && state->nInfcount > 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range.")));
 
+	result = (Interval *) palloc(sizeof(Interval));
+
 	if (state->pInfcount > 0)
-	{
 		INTERVAL_NOEND(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
-
-	if (state->nInfcount > 0)
-	{
+	else if (state->nInfcount > 0)
 		INTERVAL_NOBEGIN(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
 
-	memcpy(result, &state->sumX, sizeof(Interval));
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -4236,14 +4246,14 @@ timestamp_age(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -4252,7 +4262,7 @@ timestamp_age(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -4383,14 +4393,14 @@ timestamptz_age(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -4399,7 +4409,7 @@ timestamptz_age(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -5831,17 +5841,16 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 /*
  * NonFiniteIntervalPart
  *
- *	Used by interval_part when extracting from infinite
- *	interval.  Returns +/-Infinity if that is the appropriate result,
- *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
  *
  *	Errors thrown here for invalid units should exactly match those that
  *	would be thrown in the calling functions, else there will be unexpected
  *	discrepancies between finite- and infinite-input cases.
  */
 static float8
-NonFiniteIntervalPart(int type, int unit, char *lowunits,
-					  bool isNegative, bool isTz)
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
 {
 	if ((type != UNITS) && (type != RESERV))
 		ereport(ERROR,
@@ -5908,8 +5917,7 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (INTERVAL_NOT_FINITE(interval))
 	{
 		double		r = NonFiniteIntervalPart(type, val, lowunits,
-											  INTERVAL_IS_NOBEGIN(interval),
-											  false);
+											  INTERVAL_IS_NOBEGIN(interval));
 
 		if (r != 0.0)
 		{
@@ -6455,7 +6463,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -6478,7 +6485,7 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
@@ -6541,7 +6548,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -6565,7 +6571,7 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 0e62c3f7a6..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -47,11 +47,9 @@
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
   aggserialfn => 'interval_avg_serialize',
   aggdeserialfn => 'interval_avg_deserialize',
-  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
-  aggmtranstype => 'internal', aggtransspace => '128',
-  aggmtransspace => '128'
-},
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -79,10 +77,9 @@
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
   aggserialfn => 'interval_avg_serialize',
   aggdeserialfn => 'interval_avg_deserialize',
-  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
-  aggmtranstype => 'internal', aggtransspace => '128',
-  aggmtransspace => '128'},
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 449c1dae82..4cd348b758 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4922,9 +4922,9 @@
   prorettype => 'internal', proargtypes => 'internal internal',
   prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', proisstrict => 'f',
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
-  prosrc => 'interval_accum_inv' },
+  prosrc => 'interval_avg_accum_inv' },
 { oid => '3813', descr => 'aggregate serial function',
   proname => 'interval_avg_serialize', prorettype => 'bytea',
   proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
@@ -4932,7 +4932,7 @@
   proname => 'interval_avg_deserialize', prorettype => 'internal',
   proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
 { oid => '8069', descr => 'aggregate final function',
   proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index f9bd30d225..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,23 +168,29 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
 #define INTERVAL_NOBEGIN(i)	\
 	do {	\
-		(i->time) = PG_INT64_MIN;	\
-		(i->day) = PG_INT32_MIN;	\
-		(i->month) = PG_INT32_MIN;	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
 	} while (0)
 
-#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
 
 #define INTERVAL_NOEND(i)	\
 	do {	\
-		(i->time) = PG_INT64_MAX;	\
-		(i->day) = PG_INT32_MAX;	\
-		(i->month) = PG_INT32_MAX;	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
 	} while (0)
 
-#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
 
 #define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index fe713fb6dd..c4dd96c8c9 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,7 +118,6 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
-extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -128,8 +127,6 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
-extern double interval2timestamp_no_overflow(Interval *interval);
-
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 8bd72f60b0..00cd3e84f1 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -284,11 +284,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483646 months'),
-  ('2147483647 days -2147483647 months'),
+  ('2147483647 days 2147483647 months'),
+  ('2147483647 days -2147483648 months'),
   ('1 year'),
-  ('-2147483648 days 2147483646 months'),
-  ('-2147483648 days -2147483647 months');
+  ('-2147483648 days 2147483647 months'),
+  ('-2147483648 days -2147483648 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -315,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
- 1 year                                    | -178956970 years -7 mons -2147483648 days
- 1 year                                    | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
- 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons -2147483648 days   | 1 year
- 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
- 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons 2147483647 days    | 1 year
- 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
+ -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
+ 1 year                                    | -178956970 years -8 mons -2147483648 days
+ 1 year                                    | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
+ 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons -2147483648 days   | 1 year
+ 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
+ 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons 2147483647 days    | 1 year
+ 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -339,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -7 mons -2147483648 days
- -178956970 years -7 mons +2147483647 days
+ -178956970 years -8 mons -2147483648 days
+ -178956970 years -8 mons +2147483647 days
  1 year
- 178956970 years 6 mons -2147483648 days
- 178956970 years 6 mons 2147483647 days
+ 178956970 years 7 mons -2147483648 days
+ 178956970 years 7 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -485,9 +485,7 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483646 months 30 days');
-ERROR:  interval out of range
-SELECT justify_days(interval '2147483646 months 60 days');
+SELECT justify_days(interval '2147483647 months 30 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -508,29 +506,25 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483646 months 30 days');
-ERROR:  interval out of range
-SELECT justify_interval(interval '2147483646 months 60 days');
-ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 6 mons 29 days
+ @ 178956970 years 7 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 7 mons 29 days ago
+ @ 178956970 years 8 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -1882,233 +1876,144 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
--- infinite intervals
-SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-ERROR:  interval out of range
-LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
-                        ^
-SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
-ERROR:  interval out of range
-LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
-                        ^
-CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
-INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
-SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
-            i            | isfinite 
--------------------------+----------
- infinity                | f
- -infinity               | f
- @ 1 year 2 days 3 hours | t
-(3 rows)
-
-SELECT date '1995-08-06' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date '1995-08-06' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT date '1995-08-06' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT date '1995-08-06' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT date '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT date '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
 (1 row)
 
-SELECT date 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT date 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
 (1 row)
 
-SELECT date '-infinity' - interval 'infinity';
- ?column?  
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
 -----------
  -infinity
 (1 row)
 
-SELECT date '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' + interval 'infinity';
- ?column? 
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
 ----------
  infinity
 (1 row)
 
-SELECT interval 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT interval '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT interval '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
 
-SELECT interval 'infinity' + interval '10 days';
- ?column? 
-----------
- infinity
-(1 row)
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT interval '-infinity' + interval '10 days';
- ?column?  
------------
- -infinity
-(1 row)
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
 
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
 ERROR:  interval out of range
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
 ERROR:  interval out of range
-SELECT interval 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT interval '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT interval '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' - interval '10 days';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT interval '-infinity' - interval '10 days';
- ?column?  
------------
- -infinity
-(1 row)
-
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
 ERROR:  interval out of range
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
 ERROR:  interval out of range
-SELECT timestamp 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamp 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamp '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamp '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamp 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamp 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamp '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamp '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamptz '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamptz '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamptz 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT timestamptz '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT timestamptz '-infinity' - interval '-infinity';
-ERROR:  interval out of range
+-- time +/- infinite interval not supported
 SELECT time '11:27:42' + interval 'infinity';
 ERROR:  cannot add infinite interval to time
 SELECT time '11:27:42' + interval '-infinity';
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index 53542e076b..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2131,7 +2131,7 @@ select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12
 ERROR:  step size cannot be infinite
 -- test arithmetic with infinite timestamps
 select timestamp 'infinity' - timestamp 'infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select timestamp 'infinity' - timestamp '-infinity';
  ?column? 
 ----------
@@ -2145,7 +2145,7 @@ select timestamp '-infinity' - timestamp 'infinity';
 (1 row)
 
 select timestamp '-infinity' - timestamp '-infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
  ?column? 
 ----------
@@ -2172,7 +2172,7 @@ select age(timestamp '-infinity');
 (1 row)
 
 select age(timestamp 'infinity', timestamp 'infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select age(timestamp 'infinity', timestamp '-infinity');
    age    
 ----------
@@ -2186,4 +2186,4 @@ select age(timestamp '-infinity', timestamp 'infinity');
 (1 row)
 
 select age(timestamp '-infinity', timestamp '-infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 825202d597..1c19613ae3 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -3160,7 +3160,7 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 
 -- test arithmetic with infinite timestamps
 SELECT timestamptz 'infinity' - timestamptz 'infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT timestamptz 'infinity' - timestamptz '-infinity';
  ?column? 
 ----------
@@ -3174,7 +3174,7 @@ SELECT timestamptz '-infinity' - timestamptz 'infinity';
 (1 row)
 
 SELECT timestamptz '-infinity' - timestamptz '-infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
  ?column? 
 ----------
@@ -3201,7 +3201,7 @@ SELECT age(timestamptz '-infinity');
 (1 row)
 
 SELECT age(timestamptz 'infinity', timestamptz 'infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT age(timestamptz 'infinity', timestamptz '-infinity');
    age    
 ----------
@@ -3215,4 +3215,4 @@ SELECT age(timestamptz '-infinity', timestamptz 'infinity');
 (1 row)
 
 SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 63f36e069e..6b8c3c3413 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,9 +2419,70 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2424,7 +2490,8 @@ window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2499,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2510,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,9 +2519,70 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2460,6 +2590,7 @@ window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2601,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2610,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,7 +2621,68 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2496,6 +2690,7 @@ window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2701,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2710,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,7 +2721,68 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2532,6 +2790,7 @@ window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2801,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2810,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,7 +2821,68 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
@@ -4375,36 +4697,34 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
--- window function over interval, infinity and extreme values test the
--- behaviour of accumulation and elimination of these values as the window
--- slides.
+-- moving aggregates over infinite intervals
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
         ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
-               ('2147483647 days 2147483646 months'), -- extreme interval value
-               ('infinity'::timestamptz - now()),
-               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
                ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
-----------------------------------------------+-------------------+-------------------+---------------+----------------
-                                              | infinity          |                   | infinity      | 
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
- @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
-                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
- -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
 (10 rows)
 
 --should fail.
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 414c12be1c..1bffa50fe9 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -73,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483646 months'),
-  ('2147483647 days -2147483647 months'),
+  ('2147483647 days 2147483647 months'),
+  ('2147483647 days -2147483648 months'),
   ('1 year'),
-  ('-2147483648 days 2147483646 months'),
-  ('-2147483648 days -2147483647 months');
+  ('-2147483648 days 2147483647 months'),
+  ('-2147483648 days -2147483648 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -164,8 +164,7 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483646 months 30 days');
-SELECT justify_days(interval '2147483646 months 60 days');
+SELECT justify_days(interval '2147483647 months 30 days');
 
 -- test justify_interval()
 
@@ -173,14 +172,12 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483646 months 30 days');
-SELECT justify_interval(interval '2147483646 months 60 days');
-SELECT justify_interval(interval '-2147483647 months -30 days');
-SELECT justify_interval(interval '-2147483647 months -60 days');
-SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -608,6 +605,14 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
 -- infinite intervals
 SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
 SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
@@ -617,54 +622,64 @@ INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2
 
 SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
 
-SELECT date '1995-08-06' + interval 'infinity';
-SELECT date '1995-08-06' + interval '-infinity';
-SELECT date '1995-08-06' - interval 'infinity';
-SELECT date '1995-08-06' - interval '-infinity';
-SELECT date 'infinity' + interval 'infinity';
-SELECT date 'infinity' + interval '-infinity';
-SELECT date '-infinity' + interval 'infinity';
-SELECT date '-infinity' + interval '-infinity';
-SELECT date 'infinity' - interval 'infinity';
-SELECT date 'infinity' - interval '-infinity';
-SELECT date '-infinity' - interval 'infinity';
-SELECT date '-infinity' - interval '-infinity';
-SELECT interval 'infinity' + interval 'infinity';
-SELECT interval 'infinity' + interval '-infinity';
-SELECT interval '-infinity' + interval 'infinity';
-SELECT interval '-infinity' + interval '-infinity';
-SELECT interval 'infinity' + interval '10 days';
-SELECT interval '-infinity' + interval '10 days';
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
-SELECT interval 'infinity' - interval 'infinity';
-SELECT interval 'infinity' - interval '-infinity';
-SELECT interval '-infinity' - interval 'infinity';
-SELECT interval '-infinity' - interval '-infinity';
-SELECT interval 'infinity' - interval '10 days';
-SELECT interval '-infinity' - interval '10 days';
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
-SELECT timestamp 'infinity' + interval 'infinity';
-SELECT timestamp 'infinity' + interval '-infinity';
-SELECT timestamp '-infinity' + interval 'infinity';
-SELECT timestamp '-infinity' + interval '-infinity';
-SELECT timestamp 'infinity' - interval 'infinity';
-SELECT timestamp 'infinity' - interval '-infinity';
-SELECT timestamp '-infinity' - interval 'infinity';
-SELECT timestamp '-infinity' - interval '-infinity';
-SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
-SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
-SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
-SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
-SELECT timestamptz 'infinity' + interval 'infinity';
-SELECT timestamptz 'infinity' + interval '-infinity';
-SELECT timestamptz '-infinity' + interval 'infinity';
-SELECT timestamptz '-infinity' + interval '-infinity';
-SELECT timestamptz 'infinity' - interval 'infinity';
-SELECT timestamptz 'infinity' - interval '-infinity';
-SELECT timestamptz '-infinity' - interval 'infinity';
-SELECT timestamptz '-infinity' - interval '-infinity';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
 SELECT time '11:27:42' + interval 'infinity';
 SELECT time '11:27:42' + interval '-infinity';
 SELECT time '11:27:42' - interval 'infinity';
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 6dd9885949..c2a4cb8d64 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,21 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +721,21 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +746,21 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +771,21 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +796,21 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,19 +1668,17 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
--- window function over interval, infinity and extreme values test the
--- behaviour of accumulation and elimination of these values as the window
--- slides.
+-- moving aggregates over infinite intervals
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
         ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
-               ('2147483647 days 2147483646 months'), -- extreme interval value
-               ('infinity'::timestamptz - now()),
-               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
                ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
-- 
2.35.3

From c34c212815b40622b6cd29a314def2eaa7a5dd3e Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Tue, 10 Oct 2023 16:11:21 +0530
Subject: [PATCH 9/9] Handle infinite interval in
 brin_minmax_multi_distance_interval()

This also fixes code duplication between brin_minmax_multi_distance_interval() and interval_mi().

Adds testcase for testing infinite interval in BRIN indexes.
---
 src/backend/access/brin/brin_minmax_multi.c | 33 ++++-----------------
 src/test/regress/expected/brin_multi.out    |  9 +++---
 src/test/regress/sql/brin_multi.sql         | 10 ++++---
 3 files changed, 17 insertions(+), 35 deletions(-)

diff --git a/src/backend/access/brin/brin_minmax_multi.c b/src/backend/access/brin/brin_minmax_multi.c
index f8b2a3f9bc..61ebfb4542 100644
--- a/src/backend/access/brin/brin_minmax_multi.c
+++ b/src/backend/access/brin/brin_minmax_multi.c
@@ -2158,37 +2158,16 @@ Datum
 brin_minmax_multi_distance_interval(PG_FUNCTION_ARGS)
 {
 	float8		delta = 0;
-
-	Interval   *ia = PG_GETARG_INTERVAL_P(0);
-	Interval   *ib = PG_GETARG_INTERVAL_P(1);
 	Interval   *result;
-
 	int64		dayfraction;
 	int64		days;
 
-	result = (Interval *) palloc(sizeof(Interval));
-
-	result->month = ib->month - ia->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(ib->month, ia->month) &&
-		!SAMESIGN(result->month, ib->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = ib->day - ia->day;
-	if (!SAMESIGN(ib->day, ia->day) &&
-		!SAMESIGN(result->day, ib->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = ib->time - ia->time;
-	if (!SAMESIGN(ib->time, ia->time) &&
-		!SAMESIGN(result->time, ib->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	result = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
+												   PG_GETARG_DATUM(1),
+												   PG_GETARG_DATUM(0)));
+
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_FLOAT8(get_float8_infinity());
 
 	/*
 	 * Delta is (fractional) number of days between the intervals. Assume
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 9f46934c9b..2b48069201 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -47,6 +47,7 @@ INSERT INTO brintest_multi (inetcol, cidrcol) SELECT
 	inet 'fe80::6e40:8ff:fea9:8c46' + tenthous,
 	cidr 'fe80::6e40:8ff:fea9:8c46' + tenthous
 FROM tenk1 ORDER BY thousand, tenthous LIMIT 25;
+INSERT INTO brintest_multi(intervalcol) VALUES ('-infinity'), ('+infinity');
 -- test minmax-multi specific index options
 -- number of values must be >= 16
 CREATE INDEX brinidx_multi ON brintest_multi USING brin (
@@ -217,9 +218,9 @@ INSERT INTO brinopers_multi VALUES
 	 '{1972-10-10 03:00:00-04, 1972-10-10 03:00:00-04, 1972-10-19 09:00:00-07, 1972-11-20 19:00:00-03, 1972-11-20 19:00:00-03}',
 	 '{100, 100, 1, 100, 100}'),
 	('intervalcol', 'interval',
-	 '{>, >=, =, <=, <}',
-	 '{00:00:00, 00:00:00, 1 mons 13 days 12:24, 2 mons 23 days 07:48:00, 1 year}',
-	 '{100, 100, 1, 100, 100}'),
+	 '{>, >=, =, =, <=, <}',
+	 '{00:00:00, 00:00:00, 1 mons 13 days 12:24, infinity, 2 mons 23 days 07:48:00, 1 year}',
+	 '{101, 101, 1, 1, 101, 101}'),
 	('timetzcol', 'timetz',
 	 '{>, >=, =, <=, <}',
 	 '{01:30:20+02, 01:30:20+02, 01:35:50+02, 23:55:05+02, 23:55:05+02}',
@@ -235,7 +236,7 @@ INSERT INTO brinopers_multi VALUES
 	('lsncol', 'pg_lsn',
 	 '{>, >=, =, <=, <, IS, IS NOT}',
 	 '{0/1200, 0/1200, 44/455222, 198/1999799, 198/1999799, NULL, NULL}',
-	 '{100, 100, 1, 100, 100, 25, 100}');
+	 '{100, 100, 1, 100, 100, 27, 100}');
 DO $x$
 DECLARE
 	r record;
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index d50dbdee68..b868b5bdb9 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -50,6 +50,8 @@ INSERT INTO brintest_multi (inetcol, cidrcol) SELECT
 	cidr 'fe80::6e40:8ff:fea9:8c46' + tenthous
 FROM tenk1 ORDER BY thousand, tenthous LIMIT 25;
 
+INSERT INTO brintest_multi(intervalcol) VALUES ('-infinity'), ('+infinity');
+
 -- test minmax-multi specific index options
 -- number of values must be >= 16
 CREATE INDEX brinidx_multi ON brintest_multi USING brin (
@@ -221,9 +223,9 @@ INSERT INTO brinopers_multi VALUES
 	 '{1972-10-10 03:00:00-04, 1972-10-10 03:00:00-04, 1972-10-19 09:00:00-07, 1972-11-20 19:00:00-03, 1972-11-20 19:00:00-03}',
 	 '{100, 100, 1, 100, 100}'),
 	('intervalcol', 'interval',
-	 '{>, >=, =, <=, <}',
-	 '{00:00:00, 00:00:00, 1 mons 13 days 12:24, 2 mons 23 days 07:48:00, 1 year}',
-	 '{100, 100, 1, 100, 100}'),
+	 '{>, >=, =, =, <=, <}',
+	 '{00:00:00, 00:00:00, 1 mons 13 days 12:24, infinity, 2 mons 23 days 07:48:00, 1 year}',
+	 '{101, 101, 1, 1, 101, 101}'),
 	('timetzcol', 'timetz',
 	 '{>, >=, =, <=, <}',
 	 '{01:30:20+02, 01:30:20+02, 01:35:50+02, 23:55:05+02, 23:55:05+02}',
@@ -239,7 +241,7 @@ INSERT INTO brinopers_multi VALUES
 	('lsncol', 'pg_lsn',
 	 '{>, >=, =, <=, <, IS, IS NOT}',
 	 '{0/1200, 0/1200, 44/455222, 198/1999799, 198/1999799, NULL, NULL}',
-	 '{100, 100, 1, 100, 100, 25, 100}');
+	 '{100, 100, 1, 100, 100, 27, 100}');
 
 DO $x$
 DECLARE
-- 
2.25.1

From b5b0112984363ee6d6107e297fe883871e50fc04 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 15:34:33 +0530
Subject: [PATCH 5/9] Use integer overflow checking routines to add and
 subtract finite intervals

Use pg_add/sub_s32/64_overflow() routines in finite_interval_pl() and
finite_interval_mi() instead of adding overflow checks in those
functions.

Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c      | 121 +++++++++++--------------
 src/test/regress/expected/interval.out |  11 +++
 src/test/regress/expected/window.out   |  54 ++++-------
 src/test/regress/sql/interval.sql      |   3 +
 src/test/regress/sql/window.sql        |  22 ++---
 5 files changed, 95 insertions(+), 116 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 50fb793c13..8c1b0a774b 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -99,6 +99,8 @@ static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 static void interval_um_internal(Interval *interval, Interval *result);
 static void finite_interval_pl(Interval *result, Interval *span1,
 							   Interval *span2);
+static void finite_interval_mi(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3502,34 +3504,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-	{
-		result->month = span1->month - span2->month;
-		/* overflow check copied from int4mi */
-		if (!SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day - span2->day;
-		if (!SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time - span2->time;
-		if (!SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_mi(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3869,11 +3844,18 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Function to add two finite intervals.
+ * Functions to add or subtract two finite intervals.
+ *
+ * We handle non-finite intervals in different ways when accumulating/discarding
+ * intervals and in actual mathematical operations respectively. But the
+ * addition or subtraction of finite intervals have same implementation
+ * respectively in both these cases.
+ *
+ * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
+ * to pass either of span1 or span2 as a result pointer. In such a case result
+ * will overwrite the given value.
  *
- * We handle non-finite intervals in different ways when accumulating intervals
- * and adding two intervals respectively. But the addition of finite interval
- * has same implementation in both these cases.
+ * If the result is not a valid interval, the function throws an error.
  */
 static void
 finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
@@ -3881,24 +3863,44 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
@@ -3915,9 +3917,6 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-
-	Interval	temp;
-
 	/* Count -infinity inputs separately from all else */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
@@ -3932,8 +3931,7 @@ do_interval_accum(IntervalAggState *state, Interval *newval)
 		return;
 	}
 
-	memcpy(&temp, &state->sumX, sizeof(Interval));
-	finite_interval_pl(&state->sumX, &temp, newval);
+	finite_interval_pl(&state->sumX, &state->sumX, newval);
 	state->N++;
 }
 
@@ -3959,6 +3957,9 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 
 /*
  * Combine function for interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in the
+ * first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3972,9 +3973,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	if (state2 == NULL)
 		PG_RETURN_POINTER(state1);
 
-	/* manually copy all fields from state2 to state1 */
 	if (state1 == NULL)
 	{
+		/* manually copy all fields from state2 to state1 */
 		state1 = makeIntervalAggState(fcinfo);
 
 		state1->N = state2->N;
@@ -3992,14 +3993,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	state1->pInfcount += state2->pInfcount;
 	state1->nInfcount += state2->nInfcount;
 
+	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-	{
-		Interval	temp;
-
-		/* Accumulate interval values */
-		memcpy(&temp, &state1->sumX, sizeof(Interval));
-		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
-	}
+		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4025,24 +4021,15 @@ do_interval_discard(IntervalAggState *state, Interval *newval)
 	}
 
 	/* Handle to be discarded finite value. */
+	state->N--;
 	if (state->N > 0)
-	{
-		Interval	temp;
-		Interval	neg_val;
-
-		neg_val.day = -newval->day;
-		neg_val.month = -newval->month;
-		neg_val.time = -newval->time;
-
-		memcpy(&temp, &state->sumX, sizeof(Interval));
-		finite_interval_pl(&state->sumX, &temp, &neg_val);
-	}
+		finite_interval_mi(&state->sumX, &state->sumX, newval);
 	else
 	{
 		/* All values discarded, reset the state */
+		Assert(state->N == 0);
 		memset(&state->sumX, 0, sizeof(state->sumX));
 	}
-	state->N--;
 }
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 135d683285..8bd72f60b0 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -347,6 +347,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 45262924cd..63f36e069e 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,51 +4375,37 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-     x     | curr_next_avg | prev1_curr_sum 
------------+---------------+----------------
- -infinity | -infinity     | -infinity
- @ 6 days  | infinity      | -infinity
- infinity  | infinity      | infinity
- infinity  | infinity      | infinity
-           |               | infinity
-           |               | 
-(6 rows)
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
------------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
-           | infinity          | infinity      |                   |                | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
- @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
-           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
- -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
-(7 rows)
+                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
+----------------------------------------------+-------------------+-------------------+---------------+----------------
+                                              | infinity          |                   | infinity      | 
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
 
 --should fail.
 SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 912803a1b0..414c12be1c 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -99,6 +99,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index d00423946d..6dd9885949 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,28 +1591,20 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
-- 
2.25.1

From e85bcba3343ceb9c4a8265449e8b82b701c2b84f Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 16:52:30 +0530
Subject: [PATCH 6/9] Implement serialization functions for interval aggregate
 state

Now that interval aggregates use transition state which of date type Internal,
parallel aggregates require these separate functions.

Jian He and Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 86 +++++++++++++++++++++++++++-
 src/include/catalog/pg_aggregate.dat |  4 ++
 src/include/catalog/pg_proc.dat      |  6 ++
 3 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 8c1b0a774b..bf02ddb92d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3821,8 +3821,12 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * Prepare state data for an interval aggregate function that needs to compute
- * sum and count.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
  */
 static IntervalAggState *
 makeIntervalAggState(FunctionCallInfo fcinfo)
@@ -4000,6 +4004,84 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_serialize(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
+
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	/* TODO: Handle NULL inputs? */
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+	pq_begintypsend(&buf);
+	/* N */
+	pq_sendint64(&buf, state->N);
+	/* Finite interval value */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
+	result = pq_endtypsend(&buf);
+	PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_deserialize(PG_FUNCTION_ARGS)
+{
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	sstate = PG_GETARG_BYTEA_PP(0);
+
+	/*
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
+	 */
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
+
+	/* Interval struct elements, one by one. */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
+	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+	pfree(buf.data);
+
+	PG_RETURN_POINTER(result);
+}
+
 /*
  * Remove the given interval value from the aggregated state.
  */
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index e2087d7be1..0e62c3f7a6 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -45,6 +45,8 @@
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
 { aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
@@ -75,6 +77,8 @@
   aggtranstype => 'money', aggmtranstype => 'money' },
 { aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8eca58ddf..34da5f3687 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4925,6 +4925,12 @@
   proname => 'interval_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
   prosrc => 'interval_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
-- 
2.25.1

From 0e175da667f849e11f510bc24dc7ff6ed1aba288 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Fri, 6 Oct 2023 11:58:21 +0530
Subject: [PATCH 8/9] Add tests for "invalid preceding or following size in
 window function"

Ashutosh Bapat
---
 src/test/regress/expected/window.out | 50 ++++++++++++++++++++++++++++
 src/test/regress/sql/window.sql      | 50 ++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)

diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 6b8c3c3413..f1eaf4b58b 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2424,6 +2424,11 @@ window w as (order by f_time desc range between
   0 | 10:00:00 |           1 |          0
 (12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);
+ERROR:  invalid preceding or following size in window function
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
@@ -2484,6 +2489,11 @@ window w as (order by f_time range between
  11 | 21:00:00 |             |           
 (12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and 'infinity'::interval following);
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -2524,6 +2534,11 @@ window w as (order by f_timetz desc range between
   0 | 10:00:00+01 |           1 |          0
 (12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -2584,6 +2599,11 @@ window w as (order by f_timetz range between
  11 | 21:00:00+01 |             |           
 (12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and '-infinity'::interval following);
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -2624,6 +2644,11 @@ window w as (order by f_interval desc range between
   0 | -infinity  |           0 |          0
 (12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -2684,6 +2709,11 @@ window w as (order by f_interval range between
  11 | infinity   |          11 |         11
 (12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and 'infinity'::interval following);
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -2724,6 +2754,11 @@ window w as (order by f_timestamptz desc range between
   0 | -infinity                    |           0 |          0
 (12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -2784,6 +2819,11 @@ window w as (order by f_timestamptz range between
  11 | infinity                     |          11 |         11
 (12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and 'infinity'::interval following);
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -2824,6 +2864,11 @@ window w as (order by f_timestamp desc range between
   0 | -infinity                |           0 |          0
 (12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -2884,6 +2929,11 @@ window w as (order by f_timestamp range between
  11 | infinity                 |          11 |         11
 (12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and 'infinity'::interval following);
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index c2a4cb8d64..586ffb245d 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -696,6 +696,11 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);
+
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
@@ -711,6 +716,11 @@ from datetimes
 window w as (order by f_time range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -721,6 +731,11 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -736,6 +751,11 @@ from datetimes
 window w as (order by f_timetz range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and '-infinity'::interval following);
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -746,6 +766,11 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -761,6 +786,11 @@ from datetimes
 window w as (order by f_interval range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -771,6 +801,11 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -786,6 +821,11 @@ from datetimes
 window w as (order by f_timestamptz range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -796,6 +836,11 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -811,6 +856,11 @@ from datetimes
 window w as (order by f_timestamp range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and 'infinity'::interval following);
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
-- 
2.25.1

From 82a7d3ba92e1df0d0ebbda5cfccff25d9450aad6 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Thu, 28 Sep 2023 14:54:02 +0100
Subject: [PATCH 7/9] Code review of infinite interval support.

---
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  27 +-
 src/backend/utils/adt/datetime.c          |   4 +-
 src/backend/utils/adt/selfuncs.c          |  16 +-
 src/backend/utils/adt/timestamp.c         | 366 +++++++++----------
 src/include/catalog/pg_aggregate.dat      |  11 +-
 src/include/catalog/pg_proc.dat           |   6 +-
 src/include/datatype/timestamp.h          |  24 +-
 src/include/utils/timestamp.h             |   3 -
 src/test/regress/expected/interval.out    | 375 ++++++++------------
 src/test/regress/expected/timestamp.out   |   8 +-
 src/test/regress/expected/timestamptz.out |   8 +-
 src/test/regress/expected/window.out      | 406 +++++++++++++++++++---
 src/test/regress/sql/interval.sql         | 131 +++----
 src/test/regress/sql/window.sql           |  93 ++++-
 15 files changed, 912 insertions(+), 571 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7786853743..2fd9db9afa 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10435,7 +10435,10 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
      <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
-     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index f2107dd967..ef06474ac3 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2050,8 +2051,6 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
-	Assert(!INTERVAL_NOT_FINITE(result));
-
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2116,7 +2115,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2126,13 +2126,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2666,7 +2667,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2676,13 +2678,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 73dadb747c..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3613,9 +3613,9 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 							return DTERR_BAD_FORMAT;
 
 						/*
-						 * infinity can not be followed by anything else. We
+						 * Infinity cannot be followed by anything else. We
 						 * could allow "ago" to reverse the sign of infinity
-						 * but that signed infinity is more intuitive.
+						 * but using signed infinity is more intuitive.
 						 */
 						if (i != nf - 1)
 							return DTERR_BAD_FORMAT;
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 6e87173846..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,7 +4795,21 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
+			{
+				Interval   *interval = DatumGetIntervalP(value);
+
+				/*
+				 * Convert the month part of Interval to days using assumed
+				 * average month length of 365.25/12.0 days.  Not too
+				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
+				 */
+				return interval->time + interval->day * (double) USECS_PER_DAY +
+					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+			}
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index bf02ddb92d..c8e1fb9f9d 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,7 +18,6 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
-#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -74,16 +73,16 @@ typedef struct
 } generate_series_timestamptz_fctx;
 
 /*
- * The transition datatype for interval aggregates is declared as Internal. It's
- * a pointer to a IntervalAggState allocated in the aggregate context.
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
  */
 typedef struct IntervalAggState
 {
-	int64		N;				/* count of processed intervals */
-	Interval	sumX;			/* sum of processed intervals */
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
 	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
-	int64		pInfcount;		/* count of +Inf values */
-	int64		nInfcount;		/* count of -Inf values */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
 } IntervalAggState;
 
 #define IA_TOTAL_COUNT(ia) \
@@ -96,11 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
-static void interval_um_internal(Interval *interval, Interval *result);
-static void finite_interval_pl(Interval *result, Interval *span1,
-							   Interval *span2);
-static void finite_interval_mi(Interval *result, Interval *span1,
-							   Interval *span2);
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -1604,8 +1604,8 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
-void
-EncodeSpecialInterval(Interval *interval, char *str)
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
 {
 	if (INTERVAL_IS_NOBEGIN(interval))
 		strcpy(str, EARLY);
@@ -2101,6 +2101,13 @@ itm2interval(struct pg_itm *itm, Interval *span)
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2112,8 +2119,6 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
-	if (INTERVAL_NOT_FINITE(span))
-		return -1;
 	return 0;
 }
 
@@ -2280,29 +2285,6 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
-double
-interval2timestamp_no_overflow(Interval *interval)
-{
-	double		result;
-
-	if (INTERVAL_IS_NOBEGIN(interval))
-		result = -DBL_MAX;
-	else if (INTERVAL_IS_NOEND(interval))
-		result = DBL_MAX;
-	else
-	{
-		/*
-		 * Convert the month part of Interval to days using assumed average
-		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
-		 * good enough for our purposes.
-		 */
-		return interval->time + interval->day * (double) USECS_PER_DAY +
-			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-	}
-
-	return result;
-}
-
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2526,6 +2508,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2801,14 +2792,14 @@ timestamp_mi(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -2817,7 +2808,7 @@ timestamp_mi(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -3068,16 +3059,16 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Timestamp	result;
 
 	/*
-	 * Adding two infinites with the same sign results in an infinite
-	 * timestamp with the same sign. Adding two infintes with different signs
-	 * results in an error.
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span))
 	{
 		if (TIMESTAMP_IS_NOEND(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOBEGIN(result);
 	}
@@ -3086,7 +3077,7 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOBEGIN(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOEND(result);
 	}
@@ -3197,16 +3188,16 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	int			tz;
 
 	/*
-	 * Adding two infinites with the same sign results in an infinite
-	 * timestamp with the same sign. Adding two infintes with different signs
-	 * results in an error.
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span))
 	{
 		if (TIMESTAMP_IS_NOEND(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOBEGIN(result);
 	}
@@ -3215,7 +3206,7 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 		if (TIMESTAMP_IS_NOBEGIN(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOEND(result);
 	}
@@ -3362,16 +3353,12 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 
 /* Negates the given interval */
 static void
-interval_um_internal(Interval *interval, Interval *result)
+interval_um_internal(const Interval *interval, Interval *result)
 {
 	if (INTERVAL_IS_NOBEGIN(interval))
 		INTERVAL_NOEND(result);
 	else if (INTERVAL_IS_NOEND(interval))
 		INTERVAL_NOBEGIN(result);
-	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
 	else
 	{
 		result->time = -interval->time;
@@ -3438,8 +3425,8 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	/*
 	 * Adding two infinite intervals with the same signs results in an
-	 * infinite interval with the same sign. Adding two infinte intervals with
-	 * different signs results in an error.
+	 * infinite interval with the same sign. Adding two infinite intervals
+	 * with different signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span1))
 	{
@@ -3462,7 +3449,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-		finite_interval_pl(result, span1, span2);
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3479,7 +3466,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite intervals with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte intervals with the same sign results in an error.
+	 * two infinite intervals with the same sign results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span1))
 	{
@@ -3504,7 +3491,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-		finite_interval_mi(result, span1, span2);
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3552,13 +3539,11 @@ interval_mul(PG_FUNCTION_ARGS)
 	}
 	else if (isinf(factor))
 	{
-		Interval	zero;
 		int			factor_sign,
 					result_sign;
 
 		factor_sign = factor >= 0.0 ? 1 : -1;
-		memset(&zero, 0, sizeof(zero));
-		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+		result_sign = interval_sign(span) * factor_sign;
 
 		if (result_sign == 0)
 			ereport(ERROR,
@@ -3740,11 +3725,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3767,11 +3762,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3798,11 +3803,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3848,21 +3863,13 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Functions to add or subtract two finite intervals.
+ * Functions to add or subtract finite intervals.
  *
- * We handle non-finite intervals in different ways when accumulating/discarding
- * intervals and in actual mathematical operations respectively. But the
- * addition or subtraction of finite intervals have same implementation
- * respectively in both these cases.
- *
- * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
- * to pass either of span1 or span2 as a result pointer. In such a case result
- * will overwrite the given value.
- *
- * If the result is not a valid interval, the function throws an error.
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
  */
 static void
-finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
 {
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
@@ -3889,7 +3896,7 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 }
 
 static void
-finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
 {
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
@@ -3921,26 +3928,56 @@ finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	/* Count -infinity inputs separately from all else */
+	/* Infinite inputs are counted separately, and do not affect "N" */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
 		state->nInfcount++;
 		return;
 	}
 
-	/* Count infinity inputs separately from all else */
 	if (INTERVAL_IS_NOEND(newval))
 	{
 		state->pInfcount++;
 		return;
 	}
 
-	finite_interval_pl(&state->sumX, &state->sumX, newval);
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
 	state->N++;
 }
 
 /*
- * Transition function for interval aggregates.
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle to be discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
  */
 Datum
 interval_avg_accum(PG_FUNCTION_ARGS)
@@ -3960,10 +3997,10 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 }
 
 /*
- * Combine function for interval aggregates.
+ * Combine function for sum() and avg() interval aggregates.
  *
- * Combine the given internal aggregate states and place the combination in the
- * first argument.
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3999,7 +4036,7 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 
 	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4019,20 +4056,26 @@ interval_avg_serialize(PG_FUNCTION_ARGS)
 	if (!AggCheckCallContext(fcinfo, NULL))
 		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	/* TODO: Handle NULL inputs? */
 	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+
 	pq_begintypsend(&buf);
+
 	/* N */
 	pq_sendint64(&buf, state->N);
-	/* Finite interval value */
+
+	/* sumX */
 	pq_sendint64(&buf, state->sumX.time);
 	pq_sendint32(&buf, state->sumX.day);
 	pq_sendint32(&buf, state->sumX.month);
+
 	/* pInfcount */
 	pq_sendint64(&buf, state->pInfcount);
+
 	/* nInfcount */
 	pq_sendint64(&buf, state->nInfcount);
+
 	result = pq_endtypsend(&buf);
+
 	PG_RETURN_BYTEA_P(result);
 }
 
@@ -4065,10 +4108,10 @@ interval_avg_deserialize(PG_FUNCTION_ARGS)
 	/* N */
 	result->N = pq_getmsgint64(&buf);
 
-	/* Interval struct elements, one by one. */
+	/* sumX */
 	result->sumX.time = pq_getmsgint64(&buf);
-	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
-	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
 
 	/* pInfcount */
 	result->pInfcount = pq_getmsgint64(&buf);
@@ -4083,42 +4126,10 @@ interval_avg_deserialize(PG_FUNCTION_ARGS)
 }
 
 /*
- * Remove the given interval value from the aggregated state.
- */
-static void
-do_interval_discard(IntervalAggState *state, Interval *newval)
-{
-	/* Count -infinity inputs separately from all else */
-	if (INTERVAL_IS_NOBEGIN(newval))
-	{
-		state->nInfcount--;
-		return;
-	}
-
-	/* Count infinity inputs separately from all else */
-	if (INTERVAL_IS_NOEND(newval))
-	{
-		state->pInfcount--;
-		return;
-	}
-
-	/* Handle to be discarded finite value. */
-	state->N--;
-	if (state->N > 0)
-		finite_interval_mi(&state->sumX, &state->sumX, newval);
-	else
-	{
-		/* All values discarded, reset the state */
-		Assert(state->N == 0);
-		memset(&state->sumX, 0, sizeof(state->sumX));
-	}
-}
-
-/*
- * Generic inverse transition function for interval aggregates
+ * Inverse transition function for sum() and avg() interval aggregates.
  */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
 	IntervalAggState *state;
 
@@ -4126,7 +4137,7 @@ interval_accum_inv(PG_FUNCTION_ARGS)
 
 	/* Should not get here with no state */
 	if (state == NULL)
-		elog(ERROR, "interval_accum_inv called with NULL state");
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
 
 	if (!PG_ARGISNULL(1))
 		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
@@ -4139,38 +4150,39 @@ Datum
 interval_avg(PG_FUNCTION_ARGS)
 {
 	IntervalAggState *state;
-	double		N_datum;
-	Interval   *sumX;
 
-	sumX = (Interval *) palloc(sizeof(Interval));
 	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
+	/* If there were no non-null inputs, return NULL */
 	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	/* adding plus and minus infinities gives error */
-	if (state->pInfcount > 0 && state->nInfcount > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range.")));
-
-	if (state->pInfcount > 0)
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
 	{
-		INTERVAL_NOEND(sumX);
-		PG_RETURN_INTERVAL_P(sumX);
-	}
+		Interval   *result;
 
-	if (state->nInfcount > 0)
-	{
-		INTERVAL_NOBEGIN(sumX);
-		PG_RETURN_INTERVAL_P(sumX);
-	}
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
 
-	N_datum = (double) state->N;
-	sumX = &state->sumX;
+		PG_RETURN_INTERVAL_P(result);
+	}
 
-	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
-										Float8GetDatum(N_datum)));
+	return DirectFunctionCall2(interval_div,
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
 /* sum(interval) aggregate final function */
@@ -4180,33 +4192,31 @@ interval_sum(PG_FUNCTION_ARGS)
 	IntervalAggState *state;
 	Interval   *result;
 
-	result = (Interval *) palloc(sizeof(Interval));
-
 	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
 	/* If there were no non-null inputs, return NULL */
 	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	/* adding plus and minus interval infinities is not possible */
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
 	if (state->pInfcount > 0 && state->nInfcount > 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range.")));
 
+	result = (Interval *) palloc(sizeof(Interval));
+
 	if (state->pInfcount > 0)
-	{
 		INTERVAL_NOEND(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
-
-	if (state->nInfcount > 0)
-	{
+	else if (state->nInfcount > 0)
 		INTERVAL_NOBEGIN(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
 
-	memcpy(result, &state->sumX, sizeof(Interval));
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -4236,14 +4246,14 @@ timestamp_age(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -4252,7 +4262,7 @@ timestamp_age(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -4383,14 +4393,14 @@ timestamptz_age(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -4399,7 +4409,7 @@ timestamptz_age(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -5831,17 +5841,16 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 /*
  * NonFiniteIntervalPart
  *
- *	Used by interval_part when extracting from infinite
- *	interval.  Returns +/-Infinity if that is the appropriate result,
- *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
  *
  *	Errors thrown here for invalid units should exactly match those that
  *	would be thrown in the calling functions, else there will be unexpected
  *	discrepancies between finite- and infinite-input cases.
  */
 static float8
-NonFiniteIntervalPart(int type, int unit, char *lowunits,
-					  bool isNegative, bool isTz)
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
 {
 	if ((type != UNITS) && (type != RESERV))
 		ereport(ERROR,
@@ -5908,8 +5917,7 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (INTERVAL_NOT_FINITE(interval))
 	{
 		double		r = NonFiniteIntervalPart(type, val, lowunits,
-											  INTERVAL_IS_NOBEGIN(interval),
-											  false);
+											  INTERVAL_IS_NOBEGIN(interval));
 
 		if (r != 0.0)
 		{
@@ -6455,7 +6463,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -6478,7 +6485,7 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
@@ -6541,7 +6548,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -6565,7 +6571,7 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 0e62c3f7a6..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -47,11 +47,9 @@
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
   aggserialfn => 'interval_avg_serialize',
   aggdeserialfn => 'interval_avg_deserialize',
-  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
-  aggmtranstype => 'internal', aggtransspace => '128',
-  aggmtransspace => '128'
-},
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -79,10 +77,9 @@
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
   aggserialfn => 'interval_avg_serialize',
   aggdeserialfn => 'interval_avg_deserialize',
-  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
-  aggmtranstype => 'internal', aggtransspace => '128',
-  aggmtransspace => '128'},
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 34da5f3687..d17e916118 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4922,9 +4922,9 @@
   prorettype => 'internal', proargtypes => 'internal internal',
   prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', proisstrict => 'f',
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
-  prosrc => 'interval_accum_inv' },
+  prosrc => 'interval_avg_accum_inv' },
 { oid => '3813', descr => 'aggregate serial function',
   proname => 'interval_avg_serialize', prorettype => 'bytea',
   proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
@@ -4932,7 +4932,7 @@
   proname => 'interval_avg_deserialize', prorettype => 'internal',
   proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
 { oid => '8069', descr => 'aggregate final function',
   proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index f9bd30d225..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,23 +168,29 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
 #define INTERVAL_NOBEGIN(i)	\
 	do {	\
-		(i->time) = PG_INT64_MIN;	\
-		(i->day) = PG_INT32_MIN;	\
-		(i->month) = PG_INT32_MIN;	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
 	} while (0)
 
-#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
 
 #define INTERVAL_NOEND(i)	\
 	do {	\
-		(i->time) = PG_INT64_MAX;	\
-		(i->day) = PG_INT32_MAX;	\
-		(i->month) = PG_INT32_MAX;	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
 	} while (0)
 
-#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
 
 #define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index fe713fb6dd..c4dd96c8c9 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,7 +118,6 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
-extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -128,8 +127,6 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
-extern double interval2timestamp_no_overflow(Interval *interval);
-
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 8bd72f60b0..00cd3e84f1 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -284,11 +284,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483646 months'),
-  ('2147483647 days -2147483647 months'),
+  ('2147483647 days 2147483647 months'),
+  ('2147483647 days -2147483648 months'),
   ('1 year'),
-  ('-2147483648 days 2147483646 months'),
-  ('-2147483648 days -2147483647 months');
+  ('-2147483648 days 2147483647 months'),
+  ('-2147483648 days -2147483648 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -315,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
- 1 year                                    | -178956970 years -7 mons -2147483648 days
- 1 year                                    | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
- 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons -2147483648 days   | 1 year
- 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
- 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons 2147483647 days    | 1 year
- 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
+ -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
+ 1 year                                    | -178956970 years -8 mons -2147483648 days
+ 1 year                                    | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
+ 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons -2147483648 days   | 1 year
+ 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
+ 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons 2147483647 days    | 1 year
+ 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -339,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -7 mons -2147483648 days
- -178956970 years -7 mons +2147483647 days
+ -178956970 years -8 mons -2147483648 days
+ -178956970 years -8 mons +2147483647 days
  1 year
- 178956970 years 6 mons -2147483648 days
- 178956970 years 6 mons 2147483647 days
+ 178956970 years 7 mons -2147483648 days
+ 178956970 years 7 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -485,9 +485,7 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483646 months 30 days');
-ERROR:  interval out of range
-SELECT justify_days(interval '2147483646 months 60 days');
+SELECT justify_days(interval '2147483647 months 30 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -508,29 +506,25 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483646 months 30 days');
-ERROR:  interval out of range
-SELECT justify_interval(interval '2147483646 months 60 days');
-ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 6 mons 29 days
+ @ 178956970 years 7 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 7 mons 29 days ago
+ @ 178956970 years 8 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -1882,233 +1876,144 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
--- infinite intervals
-SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-ERROR:  interval out of range
-LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
-                        ^
-SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
-ERROR:  interval out of range
-LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
-                        ^
-CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
-INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
-SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
-            i            | isfinite 
--------------------------+----------
- infinity                | f
- -infinity               | f
- @ 1 year 2 days 3 hours | t
-(3 rows)
-
-SELECT date '1995-08-06' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date '1995-08-06' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT date '1995-08-06' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT date '1995-08-06' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT date '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT date '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
 (1 row)
 
-SELECT date 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT date 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
 (1 row)
 
-SELECT date '-infinity' - interval 'infinity';
- ?column?  
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
 -----------
  -infinity
 (1 row)
 
-SELECT date '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' + interval 'infinity';
- ?column? 
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
 ----------
  infinity
 (1 row)
 
-SELECT interval 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT interval '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT interval '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
 
-SELECT interval 'infinity' + interval '10 days';
- ?column? 
-----------
- infinity
-(1 row)
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT interval '-infinity' + interval '10 days';
- ?column?  
------------
- -infinity
-(1 row)
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
 
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
 ERROR:  interval out of range
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
 ERROR:  interval out of range
-SELECT interval 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT interval '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT interval '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' - interval '10 days';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT interval '-infinity' - interval '10 days';
- ?column?  
------------
- -infinity
-(1 row)
-
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
 ERROR:  interval out of range
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
 ERROR:  interval out of range
-SELECT timestamp 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamp 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamp '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamp '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamp 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamp 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamp '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamp '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamptz '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamptz '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamptz 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT timestamptz '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT timestamptz '-infinity' - interval '-infinity';
-ERROR:  interval out of range
+-- time +/- infinite interval not supported
 SELECT time '11:27:42' + interval 'infinity';
 ERROR:  cannot add infinite interval to time
 SELECT time '11:27:42' + interval '-infinity';
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index 53542e076b..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2131,7 +2131,7 @@ select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12
 ERROR:  step size cannot be infinite
 -- test arithmetic with infinite timestamps
 select timestamp 'infinity' - timestamp 'infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select timestamp 'infinity' - timestamp '-infinity';
  ?column? 
 ----------
@@ -2145,7 +2145,7 @@ select timestamp '-infinity' - timestamp 'infinity';
 (1 row)
 
 select timestamp '-infinity' - timestamp '-infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
  ?column? 
 ----------
@@ -2172,7 +2172,7 @@ select age(timestamp '-infinity');
 (1 row)
 
 select age(timestamp 'infinity', timestamp 'infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select age(timestamp 'infinity', timestamp '-infinity');
    age    
 ----------
@@ -2186,4 +2186,4 @@ select age(timestamp '-infinity', timestamp 'infinity');
 (1 row)
 
 select age(timestamp '-infinity', timestamp '-infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 825202d597..1c19613ae3 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -3160,7 +3160,7 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 
 -- test arithmetic with infinite timestamps
 SELECT timestamptz 'infinity' - timestamptz 'infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT timestamptz 'infinity' - timestamptz '-infinity';
  ?column? 
 ----------
@@ -3174,7 +3174,7 @@ SELECT timestamptz '-infinity' - timestamptz 'infinity';
 (1 row)
 
 SELECT timestamptz '-infinity' - timestamptz '-infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
  ?column? 
 ----------
@@ -3201,7 +3201,7 @@ SELECT age(timestamptz '-infinity');
 (1 row)
 
 SELECT age(timestamptz 'infinity', timestamptz 'infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT age(timestamptz 'infinity', timestamptz '-infinity');
    age    
 ----------
@@ -3215,4 +3215,4 @@ SELECT age(timestamptz '-infinity', timestamptz 'infinity');
 (1 row)
 
 SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 63f36e069e..6b8c3c3413 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,9 +2419,70 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2424,7 +2490,8 @@ window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2499,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2510,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,9 +2519,70 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2460,6 +2590,7 @@ window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2601,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2610,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,7 +2621,68 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2496,6 +2690,7 @@ window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2701,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2710,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,7 +2721,68 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2532,6 +2790,7 @@ window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2801,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2810,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,7 +2821,68 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
@@ -4375,36 +4697,34 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
--- window function over interval, infinity and extreme values test the
--- behaviour of accumulation and elimination of these values as the window
--- slides.
+-- moving aggregates over infinite intervals
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
         ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
-               ('2147483647 days 2147483646 months'), -- extreme interval value
-               ('infinity'::timestamptz - now()),
-               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
                ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
-----------------------------------------------+-------------------+-------------------+---------------+----------------
-                                              | infinity          |                   | infinity      | 
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
- @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
-                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
- -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
 (10 rows)
 
 --should fail.
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 414c12be1c..1bffa50fe9 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -73,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483646 months'),
-  ('2147483647 days -2147483647 months'),
+  ('2147483647 days 2147483647 months'),
+  ('2147483647 days -2147483648 months'),
   ('1 year'),
-  ('-2147483648 days 2147483646 months'),
-  ('-2147483648 days -2147483647 months');
+  ('-2147483648 days 2147483647 months'),
+  ('-2147483648 days -2147483648 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -164,8 +164,7 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483646 months 30 days');
-SELECT justify_days(interval '2147483646 months 60 days');
+SELECT justify_days(interval '2147483647 months 30 days');
 
 -- test justify_interval()
 
@@ -173,14 +172,12 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483646 months 30 days');
-SELECT justify_interval(interval '2147483646 months 60 days');
-SELECT justify_interval(interval '-2147483647 months -30 days');
-SELECT justify_interval(interval '-2147483647 months -60 days');
-SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -608,6 +605,14 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
 -- infinite intervals
 SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
 SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
@@ -617,54 +622,64 @@ INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2
 
 SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
 
-SELECT date '1995-08-06' + interval 'infinity';
-SELECT date '1995-08-06' + interval '-infinity';
-SELECT date '1995-08-06' - interval 'infinity';
-SELECT date '1995-08-06' - interval '-infinity';
-SELECT date 'infinity' + interval 'infinity';
-SELECT date 'infinity' + interval '-infinity';
-SELECT date '-infinity' + interval 'infinity';
-SELECT date '-infinity' + interval '-infinity';
-SELECT date 'infinity' - interval 'infinity';
-SELECT date 'infinity' - interval '-infinity';
-SELECT date '-infinity' - interval 'infinity';
-SELECT date '-infinity' - interval '-infinity';
-SELECT interval 'infinity' + interval 'infinity';
-SELECT interval 'infinity' + interval '-infinity';
-SELECT interval '-infinity' + interval 'infinity';
-SELECT interval '-infinity' + interval '-infinity';
-SELECT interval 'infinity' + interval '10 days';
-SELECT interval '-infinity' + interval '10 days';
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
-SELECT interval 'infinity' - interval 'infinity';
-SELECT interval 'infinity' - interval '-infinity';
-SELECT interval '-infinity' - interval 'infinity';
-SELECT interval '-infinity' - interval '-infinity';
-SELECT interval 'infinity' - interval '10 days';
-SELECT interval '-infinity' - interval '10 days';
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
-SELECT timestamp 'infinity' + interval 'infinity';
-SELECT timestamp 'infinity' + interval '-infinity';
-SELECT timestamp '-infinity' + interval 'infinity';
-SELECT timestamp '-infinity' + interval '-infinity';
-SELECT timestamp 'infinity' - interval 'infinity';
-SELECT timestamp 'infinity' - interval '-infinity';
-SELECT timestamp '-infinity' - interval 'infinity';
-SELECT timestamp '-infinity' - interval '-infinity';
-SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
-SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
-SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
-SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
-SELECT timestamptz 'infinity' + interval 'infinity';
-SELECT timestamptz 'infinity' + interval '-infinity';
-SELECT timestamptz '-infinity' + interval 'infinity';
-SELECT timestamptz '-infinity' + interval '-infinity';
-SELECT timestamptz 'infinity' - interval 'infinity';
-SELECT timestamptz 'infinity' - interval '-infinity';
-SELECT timestamptz '-infinity' - interval 'infinity';
-SELECT timestamptz '-infinity' - interval '-infinity';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
 SELECT time '11:27:42' + interval 'infinity';
 SELECT time '11:27:42' + interval '-infinity';
 SELECT time '11:27:42' - interval 'infinity';
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 6dd9885949..c2a4cb8d64 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,21 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +721,21 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +746,21 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +771,21 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +796,21 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,19 +1668,17 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
--- window function over interval, infinity and extreme values test the
--- behaviour of accumulation and elimination of these values as the window
--- slides.
+-- moving aggregates over infinite intervals
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
         ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
-               ('2147483647 days 2147483646 months'), -- extreme interval value
-               ('infinity'::timestamptz - now()),
-               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
                ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
-- 
2.25.1

From 04fe3be000f84762ca37c70d3fabc79903a6bc51 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 20 Sep 2023 15:41:00 +0530
Subject: [PATCH 4/9] Support infinite interval values in sum and avg window
 functions

Results of arithmetic operations involing both infinity and -infinity
intervals are undefined. Sliding window functions
accumulate and discard values as the window slides through the data.
Even if the data may have both infinities, none of windows may have both
of them together and thus produce definite results. Hence we can not use
normal operator functions to accumulate and discard values. Instead we
maintain a count of both infinities seen respectively in an aggregate
state and compute the aggregate for each window based on the accumulated
finite value and the counts of infinities, all of which are updated as
the window slides through the data.

Initial patch by Jian He, significantly edited by Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 407 ++++++++++++++++++---------
 src/include/catalog/pg_aggregate.dat |  23 +-
 src/include/catalog/pg_proc.dat      |  20 +-
 src/test/regress/expected/window.out |  62 ++++
 src/test/regress/sql/window.sql      |  43 +++
 src/tools/pgindent/typedefs.list     |   1 +
 6 files changed, 400 insertions(+), 156 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index c52bdb68da..50fb793c13 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,6 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as Internal. It's
+ * a pointer to a IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of processed intervals */
+	Interval	sumX;			/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -82,6 +97,8 @@ static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
 static void interval_um_internal(Interval *interval, Interval *result);
+static void finite_interval_pl(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3443,34 +3460,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-	{
-		result->month = span1->month + span2->month;
-		/* overflow check copied from int4pl */
-		if (SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day + span2->day;
-		if (SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time + span2->time;
-		if (SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_pl(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3856,161 +3846,300 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function that needs to compute
+ * sum and count.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Function to add two finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * We handle non-finite intervals in different ways when accumulating intervals
+ * and adding two intervals respectively. But the addition of finite interval
+ * has same implementation in both these cases.
  */
+static void
+finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
-Datum
-interval_accum(PG_FUNCTION_ARGS)
+	result->month = span1->month + span2->month;
+	/* overflow check copied from int4pl */
+	if (SAMESIGN(span1->month, span2->month) &&
+		!SAMESIGN(result->month, span1->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = span1->day + span2->day;
+	if (SAMESIGN(span1->day, span2->day) &&
+		!SAMESIGN(result->day, span1->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->time = span1->time + span2->time;
+	if (SAMESIGN(span1->time, span2->time) &&
+		!SAMESIGN(result->time, span1->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	Interval	temp;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	memcpy(&temp, &state->sumX, sizeof(Interval));
+	finite_interval_pl(&state->sumX, &temp, newval);
+	state->N++;
+}
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+/*
+ * Transition function for interval aggregates.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/*
+ * Combine function for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_combine(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
 
-	Interval   *newsum;
-	ArrayType  *result;
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		state1 = makeIntervalAggState(fcinfo);
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		Interval	temp;
+
+		/* Accumulate interval values */
+		memcpy(&temp, &state1->sumX, sizeof(Interval));
+		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
+	}
+
+	PG_RETURN_POINTER(state1);
+}
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* Handle to be discarded finite value. */
+	if (state->N > 0)
+	{
+		Interval	temp;
+		Interval	neg_val;
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+		neg_val.day = -newval->day;
+		neg_val.month = -newval->month;
+		neg_val.time = -newval->time;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+		memcpy(&temp, &state->sumX, sizeof(Interval));
+		finite_interval_pl(&state->sumX, &temp, &neg_val);
+	}
+	else
+	{
+		/* All values discarded, reset the state */
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+	state->N--;
 }
 
+/*
+ * Generic inverse transition function for interval aggregates
+ */
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	double		N_datum;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = (double) state->N;
+	sumX = &state->sumX;
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
+										Float8GetDatum(N_datum)));
 }
 
+/* sum(interval) aggregate final function */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_sum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+	Interval   *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	result = (Interval *) palloc(sizeof(Interval));
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
-}
+	/* adding plus and minus interval infinities is not possible */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
 
+	memcpy(result, &state->sumX, sizeof(Interval));
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e2087d7be1 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,12 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9805bc6118..f8eca58ddf 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4914,17 +4914,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..45262924cd 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,68 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum 
+-----------+---------------+----------------
+ -infinity | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity
+ infinity  | infinity      | infinity
+ infinity  | infinity      | infinity
+           |               | infinity
+           |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..d00423946d 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,49 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f3d8a2a855..4df61a69ca 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1204,6 +1204,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.25.1

From 7091b79c8de43126b474cc1d44ffe1436bae1077 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH 3/9] Introduce 'infinity' interval specification in
 DecodeInterval()

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Infinte interval specification i.e. "+infinity", "-infinity" or
"infinity" does not require anything other that one of the three
strings. Fix DecodeInterval() to disallow anything else.

"ago" may be used to revrse the sign of infinity specification like how
ago reverts the sign of finite intervals. But that is not as intuitive
as it is with finite intervals. Hence disallows "infinity ago" as well.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       | 24 ++++++++++++++++
 src/test/regress/expected/interval.out | 39 ++++++++++++++++++++++++++
 src/test/regress/sql/interval.sql      | 14 +++++++++
 3 files changed, 77 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index ea2bc65f50..73dadb747c 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3599,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * infinity can not be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but that signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 5011fc4815..135d683285 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2264,3 +2264,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 590e1000bd..912803a1b0 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -745,3 +745,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
-- 
2.25.1

From 1920e8f29eada764f9206ed99b6565035d7415fd Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH 1/9] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 39 ++++++++++++++++++--------
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out | 27 ++++++++++++++++++
 src/test/regress/sql/interval.sql      | 15 ++++++++++
 4 files changed, 71 insertions(+), 11 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0e50aaec5a..7ddf64ad2e 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1509,24 +1509,41 @@ make_interval(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	/*
-	 * Reject out-of-range inputs.  We really ought to check the integer
-	 * inputs as well, but it's not entirely clear what limits to apply.
+	 * Reject out-of-range inputs.  We reject any input values that cause
+	 * integer overflow of the corresponding interval fields.
 	 */
 	if (isinf(secs) || isnan(secs))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		goto out_of_range;
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	/* years and months -> months */
+	if (pg_mul_s32_overflow(years, MONTHS_PER_YEAR, &result->month) ||
+		pg_add_s32_overflow(result->month, months, &result->month))
+		goto out_of_range;
+
+	/* weeks and days -> days */
+	if (pg_mul_s32_overflow(weeks, DAYS_PER_WEEK, &result->day) ||
+		pg_add_s32_overflow(result->day, days, &result->day))
+		goto out_of_range;
+
+	/* hours and mins -> usecs (cannot overflow 64-bit) */
+	result->time = hours * USECS_PER_HOUR + mins * USECS_PER_MINUTE;
+
+	/* secs -> usecs */
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs) ||
+		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
+		goto out_of_range;
 
 	PG_RETURN_INTERVAL_P(result);
+
+out_of_range:
+	ereport(ERROR,
+			errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+			errmsg("interval out of range"));
+
+	PG_RETURN_NULL();			/* keep compiler quiet */
 }
 
 /* EncodeSpecialTimestamp()
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e041b..75d19d6594 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,33 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(years := 178956971);
+ERROR:  interval out of range
+select make_interval(years := -178956971);
+ERROR:  interval out of range
+select make_interval(years := 1, months := 2147483647);
+ERROR:  interval out of range
+select make_interval(years := -1, months := -2147483648);
+ERROR:  interval out of range
+select make_interval(weeks := 306783379);
+ERROR:  interval out of range
+select make_interval(weeks := -306783379);
+ERROR:  interval out of range
+select make_interval(weeks := 1, days := 2147483647);
+ERROR:  interval out of range
+select make_interval(weeks := -1, days := -2147483648);
+ERROR:  interval out of range
+select make_interval(secs := 1e308);
+ERROR:  value out of range: overflow
+select make_interval(secs := 1e18);
+ERROR:  interval out of range
+select make_interval(secs := -1e18);
+ERROR:  interval out of range
+select make_interval(mins := 1, secs := 9223372036800.0);
+ERROR:  interval out of range
+select make_interval(mins := -1, secs := -9223372036800.0);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508d0..a0a373f08b 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,21 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(years := 178956971);
+select make_interval(years := -178956971);
+select make_interval(years := 1, months := 2147483647);
+select make_interval(years := -1, months := -2147483648);
+select make_interval(weeks := 306783379);
+select make_interval(weeks := -306783379);
+select make_interval(weeks := 1, days := 2147483647);
+select make_interval(weeks := -1, days := -2147483648);
+select make_interval(secs := 1e308);
+select make_interval(secs := 1e18);
+select make_interval(secs := -1e18);
+select make_interval(mins := 1, secs := 9223372036800.0);
+select make_interval(mins := -1, secs := -9223372036800.0);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.25.1

From 7a6c9d0ecb7decbd01a92bf3c32203e12a1c6320 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH 2/9] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   4 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 704 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1543 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 8d32a8c9c5..557b81cae8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2320,12 +2320,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 24ad87f910..7786853743 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ae0f24de2c..f2107dd967 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3104,6 +3131,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..ea2bc65f50 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3574,6 +3574,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index e27ea8ef97..e9e85503f8 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 7ddf64ad2e..c52bdb68da 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1558,9 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1585,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2038,6 +2074,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2055,6 +2093,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2088,7 +2128,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2219,6 +2261,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2714,46 +2779,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2783,6 +2873,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2835,6 +2928,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2858,6 +2956,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2875,6 +2976,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2896,6 +3002,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2914,6 +3023,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2934,7 +3048,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3150,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3177,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3290,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3341,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3373,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3417,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3484,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3564,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3667,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3703,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3747,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3726,8 +4035,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4182,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4335,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4523,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4766,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5116,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5390,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5630,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5707,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +5977,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6214,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5813,6 +6287,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5895,6 +6374,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..5011fc4815 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1669,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1772,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1860,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1871,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 0dd2fe2c82..825202d597 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3154,3 +3158,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..590e1000bd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -528,13 +535,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +605,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 69b36d0420..7876225c25 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -619,3 +621,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.25.1

From 8d2ddd6e0cd71e5054219d6ad7629ef715ed4ba4 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 13 Sep 2023 12:43:49 +0530
Subject: [PATCH v27 3/8] Introduce 'infinity' interval specification in
 DecodeInterval()

This reverts commit d6d1430f404386162831bc32906ad174b2007776 since
RESERVE is required to support infinite intervals. 'infinity' is saved
as a RESERVE in datetktbl[], thus required to parse
'infinity'::interval.

Infinte interval specification i.e. "+infinity", "-infinity" or
"infinity" does not require anything other that one of the three
strings. Fix DecodeInterval() to disallow anything else.

"ago" may be used to revrse the sign of infinity specification like how
ago reverts the sign of finite intervals. But that is not as intuitive
as it is with finite intervals. Hence disallows "infinity ago" as well.

Ashutosh Bapat
---
 src/backend/utils/adt/datetime.c       | 24 ++++++++++++++++
 src/test/regress/expected/interval.out | 39 ++++++++++++++++++++++++++
 src/test/regress/sql/interval.sql      | 14 +++++++++
 3 files changed, 77 insertions(+)

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index ea2bc65f50..73dadb747c 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3599,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * infinity can not be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but that signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 5011fc4815..135d683285 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2264,3 +2264,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 590e1000bd..912803a1b0 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -745,3 +745,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
-- 
2.35.3

From 8274dfa6009903de9c71b1701740100870f4a3f4 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH v27 2/8] Add infinite interval values

This commit adds positive and negative infinite values to the interval
data type. The entire range of intervals with INT_MAX months or INT_MIN
months are reserved for infinite values. This makes checking finiteness
much simpler.

Ashutosh Bapat and Joe Koshakow and Jian He
---
 doc/src/sgml/datatype.sgml                |   4 +-
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  34 ++
 src/backend/utils/adt/datetime.c          |   2 +
 src/backend/utils/adt/formatting.c        |   2 +-
 src/backend/utils/adt/selfuncs.c          |  12 +-
 src/backend/utils/adt/timestamp.c         | 704 ++++++++++++++++++----
 src/include/datatype/timestamp.h          |  19 +
 src/include/utils/timestamp.h             |   3 +
 src/test/regress/expected/horology.out    |  73 ++-
 src/test/regress/expected/interval.out    | 554 +++++++++++++++--
 src/test/regress/expected/timestamp.out   |  62 ++
 src/test/regress/expected/timestamptz.out |  62 ++
 src/test/regress/sql/horology.sql         |   5 +-
 src/test/regress/sql/interval.sql         | 172 +++++-
 src/test/regress/sql/timestamp.sql        |  19 +
 src/test/regress/sql/timestamptz.sql      |  18 +
 17 files changed, 1543 insertions(+), 207 deletions(-)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5d23765705..123d8207f8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,12 +2321,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7c3e940afe..c4f09df544 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,8 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 56c7746c11..ad97f07601 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2014,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2045,6 +2050,8 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
+	Assert(!INTERVAL_NOT_FINITE(result));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2058,6 +2065,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2088,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2590,6 +2607,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2634,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -3105,6 +3132,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..ea2bc65f50 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3574,6 +3574,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..6e87173846 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,17 +4795,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			{
-				Interval   *interval = DatumGetIntervalP(value);
-
-				/*
-				 * Convert the month part of Interval to days using assumed
-				 * average month length of 365.25/12.0 days.  Not too
-				 * accurate, but plenty good enough for our purposes.
-				 */
-				return interval->time + interval->day * (double) USECS_PER_DAY +
-					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-			}
+			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..a70639db58 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -80,6 +81,7 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void interval_um_internal(Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +943,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +973,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1365,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1558,9 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1585,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+void
+EncodeSpecialInterval(Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2038,6 +2074,8 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2055,6 +2093,8 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
@@ -2088,7 +2128,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2219,6 +2261,29 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
+double
+interval2timestamp_no_overflow(Interval *interval)
+{
+	double		result;
+
+	if (INTERVAL_IS_NOBEGIN(interval))
+		result = -DBL_MAX;
+	else if (INTERVAL_IS_NOEND(interval))
+		result = DBL_MAX;
+	else
+	{
+		/*
+		 * Convert the month part of Interval to days using assumed average
+		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
+		 * good enough for our purposes.
+		 */
+		return interval->time + interval->day * (double) USECS_PER_DAY +
+			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+	}
+
+	return result;
+}
+
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2714,46 +2779,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2783,6 +2873,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2835,6 +2928,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2858,6 +2956,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2875,6 +2976,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2896,6 +3002,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2914,6 +3023,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2934,7 +3048,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3150,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3177,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinites with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infintes with different signs
+	 * results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3290,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3341,31 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3373,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3417,60 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinte intervals with
+	 * different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+	{
+		result->month = span1->month + span2->month;
+		/* overflow check copied from int4pl */
+		if (SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day + span2->day;
+		if (SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time + span2->time;
+		if (SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3484,62 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->month = span1->month - span2->month;
+		/* overflow check copied from int4mi */
+		if (!SAMESIGN(span1->month, span2->month) &&
+			!SAMESIGN(result->month, span1->month))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->day = span1->day - span2->day;
+		if (!SAMESIGN(span1->day, span2->day) &&
+			!SAMESIGN(result->day, span1->day))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		result->time = span1->time - span2->time;
+		if (!SAMESIGN(span1->time, span2->time) &&
+			!SAMESIGN(result->time, span1->time))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3564,49 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		Interval	zero;
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		memset(&zero, 0, sizeof(zero));
+		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3667,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3703,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3747,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3726,8 +4035,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4182,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinte timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4335,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4523,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4766,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5116,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5390,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5630,59 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite
+ *	interval.  Returns +/-Infinity if that is the appropriate result,
+ *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits,
+					  bool isNegative, bool isTz)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5707,34 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval),
+											  false);
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +5977,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6214,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5813,6 +6287,11 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5895,6 +6374,11 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..f9bd30d225 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -168,6 +168,25 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i->time) = PG_INT64_MIN;	\
+		(i->day) = PG_INT32_MIN;	\
+		(i->month) = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i->time) = PG_INT64_MAX;	\
+		(i->day) = PG_INT32_MAX;	\
+		(i->month) = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index c4dd96c8c9..fe713fb6dd 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,6 +118,7 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
+extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -127,6 +128,8 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
+extern double interval2timestamp_no_overflow(Interval *interval);
+
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..5011fc4815 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,16 +268,27 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -272,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons -2147483648 days
- 1 year                                    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons -2147483648 days   | 1 year
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
- 178956970 years 7 mons 2147483647 days    | 1 year
- 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons -2147483648 days
+ 1 year                                    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons -2147483648 days   | 1 year
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
+ 178956970 years 6 mons 2147483647 days    | 1 year
+ 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -296,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -8 mons -2147483648 days
- -178956970 years -8 mons +2147483647 days
+ -178956970 years -7 mons -2147483648 days
+ -178956970 years -7 mons +2147483647 days
  1 year
- 178956970 years 7 mons -2147483648 days
- 178956970 years 7 mons 2147483647 days
+ 178956970 years 6 mons -2147483648 days
+ 178956970 years 6 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -386,12 +429,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -429,7 +474,9 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483646 months 60 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -450,25 +497,29 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '2147483646 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 60 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 7 mons 29 days
+ @ 178956970 years 6 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 8 mons 29 days ago
+ @ 178956970 years 7 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -820,8 +871,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +883,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1669,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1772,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1860,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1871,381 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
+                        ^
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ERROR:  interval out of range
+LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
+                        ^
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+SELECT date '1995-08-06' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '1995-08-06' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '1995-08-06' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT date '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT date 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT date '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT date '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' + interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' + interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' - interval '10 days';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '-infinity' - interval '10 days';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamp 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamp '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval 'infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz 'infinity' + interval '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz '-infinity' + interval '-infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz 'infinity' - interval 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - interval '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - interval '-infinity';
+ERROR:  interval out of range
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..53542e076b 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  timestamp out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  timestamp out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..e3f0d918b9 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  timestamp out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  timestamp out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  timestamp out of range
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..590e1000bd 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -69,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483647 months'),
-  ('2147483647 days -2147483648 months'),
+  ('2147483647 days 2147483646 months'),
+  ('2147483647 days -2147483647 months'),
   ('1 year'),
-  ('-2147483648 days 2147483647 months'),
-  ('-2147483648 days -2147483648 months');
+  ('-2147483648 days 2147483646 months'),
+  ('-2147483648 days -2147483647 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -140,7 +144,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -157,7 +161,8 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483647 months 30 days');
+SELECT justify_days(interval '2147483646 months 30 days');
+SELECT justify_days(interval '2147483646 months 60 days');
 
 -- test justify_interval()
 
@@ -165,12 +170,14 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483647 months 30 days');
-SELECT justify_interval(interval '-2147483648 months -30 days');
-SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483646 months 30 days');
+SELECT justify_interval(interval '2147483646 months 60 days');
+SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -528,13 +535,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +605,139 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+SELECT date '1995-08-06' + interval 'infinity';
+SELECT date '1995-08-06' + interval '-infinity';
+SELECT date '1995-08-06' - interval 'infinity';
+SELECT date '1995-08-06' - interval '-infinity';
+SELECT date 'infinity' + interval 'infinity';
+SELECT date 'infinity' + interval '-infinity';
+SELECT date '-infinity' + interval 'infinity';
+SELECT date '-infinity' + interval '-infinity';
+SELECT date 'infinity' - interval 'infinity';
+SELECT date 'infinity' - interval '-infinity';
+SELECT date '-infinity' - interval 'infinity';
+SELECT date '-infinity' - interval '-infinity';
+SELECT interval 'infinity' + interval 'infinity';
+SELECT interval 'infinity' + interval '-infinity';
+SELECT interval '-infinity' + interval 'infinity';
+SELECT interval '-infinity' + interval '-infinity';
+SELECT interval 'infinity' + interval '10 days';
+SELECT interval '-infinity' + interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval 'infinity' - interval 'infinity';
+SELECT interval 'infinity' - interval '-infinity';
+SELECT interval '-infinity' - interval 'infinity';
+SELECT interval '-infinity' - interval '-infinity';
+SELECT interval 'infinity' - interval '10 days';
+SELECT interval '-infinity' - interval '10 days';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+SELECT timestamp 'infinity' + interval 'infinity';
+SELECT timestamp 'infinity' + interval '-infinity';
+SELECT timestamp '-infinity' + interval 'infinity';
+SELECT timestamp '-infinity' + interval '-infinity';
+SELECT timestamp 'infinity' - interval 'infinity';
+SELECT timestamp 'infinity' - interval '-infinity';
+SELECT timestamp '-infinity' - interval 'infinity';
+SELECT timestamp '-infinity' - interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
+SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
+SELECT timestamptz 'infinity' + interval 'infinity';
+SELECT timestamptz 'infinity' + interval '-infinity';
+SELECT timestamptz '-infinity' + interval 'infinity';
+SELECT timestamptz '-infinity' + interval '-infinity';
+SELECT timestamptz 'infinity' - interval 'infinity';
+SELECT timestamptz 'infinity' - interval '-infinity';
+SELECT timestamptz '-infinity' - interval 'infinity';
+SELECT timestamptz '-infinity' - interval '-infinity';
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-- 
2.35.3

From eeb03c4bddf07385372dda44558874a9f25dbb1b Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Wed, 20 Sep 2023 15:41:00 +0530
Subject: [PATCH v27 4/8] Support infinite interval values in sum and avg
 window functions

Results of arithmetic operations involing both infinity and -infinity
intervals are undefined. Sliding window functions
accumulate and discard values as the window slides through the data.
Even if the data may have both infinities, none of windows may have both
of them together and thus produce definite results. Hence we can not use
normal operator functions to accumulate and discard values. Instead we
maintain a count of both infinities seen respectively in an aggregate
state and compute the aggregate for each window based on the accumulated
finite value and the counts of infinities, all of which are updated as
the window slides through the data.

Initial patch by Jian He, significantly edited by Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 407 ++++++++++++++++++---------
 src/include/catalog/pg_aggregate.dat |  23 +-
 src/include/catalog/pg_proc.dat      |  20 +-
 src/test/regress/expected/window.out |  62 ++++
 src/test/regress/sql/window.sql      |  43 +++
 src/tools/pgindent/typedefs.list     |   1 +
 6 files changed, 400 insertions(+), 156 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index a70639db58..450b547036 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -73,6 +73,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as Internal. It's
+ * a pointer to a IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of processed intervals */
+	Interval	sumX;			/* sum of processed intervals */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +Inf values */
+	int64		nInfcount;		/* count of -Inf values */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -82,6 +97,8 @@ static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
 static void interval_um_internal(Interval *interval, Interval *result);
+static void finite_interval_pl(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3443,34 +3460,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-	{
-		result->month = span1->month + span2->month;
-		/* overflow check copied from int4pl */
-		if (SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day + span2->day;
-		if (SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time + span2->time;
-		if (SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_pl(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3856,161 +3846,300 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function that needs to compute
+ * sum and count.
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Function to add two finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * We handle non-finite intervals in different ways when accumulating intervals
+ * and adding two intervals respectively. But the addition of finite interval
+ * has same implementation in both these cases.
  */
+static void
+finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
-Datum
-interval_accum(PG_FUNCTION_ARGS)
+	result->month = span1->month + span2->month;
+	/* overflow check copied from int4pl */
+	if (SAMESIGN(span1->month, span2->month) &&
+		!SAMESIGN(result->month, span1->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->day = span1->day + span2->day;
+	if (SAMESIGN(span1->day, span2->day) &&
+		!SAMESIGN(result->day, span1->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	result->time = span1->time + span2->time;
+	if (SAMESIGN(span1->time, span2->time) &&
+		!SAMESIGN(result->time, span1->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	Interval	temp;
+
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	memcpy(&temp, &state->sumX, sizeof(Interval));
+	finite_interval_pl(&state->sumX, &temp, newval);
+	state->N++;
+}
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+/*
+ * Transition function for interval aggregates.
+ */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state);
 }
 
+/*
+ * Combine function for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_combine(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
 
-	Interval   *newsum;
-	ArrayType  *result;
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	/* manually copy all fields from state2 to state1 */
+	if (state1 == NULL)
+	{
+		state1 = makeIntervalAggState(fcinfo);
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	if (state2->N > 0)
+	{
+		Interval	temp;
+
+		/* Accumulate interval values */
+		memcpy(&temp, &state1->sumX, sizeof(Interval));
+		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
+	}
+
+	PG_RETURN_POINTER(state1);
+}
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Count -infinity inputs separately from all else */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* Count infinity inputs separately from all else */
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* Handle to be discarded finite value. */
+	if (state->N > 0)
+	{
+		Interval	temp;
+		Interval	neg_val;
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+		neg_val.day = -newval->day;
+		neg_val.month = -newval->month;
+		neg_val.time = -newval->time;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+		memcpy(&temp, &state->sumX, sizeof(Interval));
+		finite_interval_pl(&state->sumX, &temp, &neg_val);
+	}
+	else
+	{
+		/* All values discarded, reset the state */
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+	state->N--;
 }
 
+/*
+ * Generic inverse transition function for interval aggregates
+ */
 Datum
 interval_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_accum_inv called with NULL state");
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	double		N_datum;
+	Interval   *sumX;
+
+	sumX = (Interval *) palloc(sizeof(Interval));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* adding plus and minus infinities gives error */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(sumX);
+		PG_RETURN_INTERVAL_P(sumX);
+	}
+
+	N_datum = (double) state->N;
+	sumX = &state->sumX;
+
+	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
+										Float8GetDatum(N_datum)));
 }
 
+/* sum(interval) aggregate final function */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_sum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+	Interval   *result;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	result = (Interval *) palloc(sizeof(Interval));
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
-}
+	/* adding plus and minus interval infinities is not possible */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	if (state->pInfcount > 0)
+	{
+		INTERVAL_NOEND(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
+
+	if (state->nInfcount > 0)
+	{
+		INTERVAL_NOBEGIN(result);
+		PG_RETURN_INTERVAL_P(result);
+	}
 
+	memcpy(result, &state->sumX, sizeof(Interval));
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e2087d7be1 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'
+},
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,12 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggmtranstype => 'internal', aggtransspace => '128',
+  aggmtransspace => '128'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index bc41e92677..791359a6e0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,23 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_accum_inv' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..45262924cd 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,6 +4375,68 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     | curr_next_avg | prev1_curr_sum 
+-----------+---------------+----------------
+ -infinity | -infinity     | -infinity
+ @ 6 days  | infinity      | -infinity
+ infinity  | infinity      | infinity
+ infinity  | infinity      | infinity
+           |               | infinity
+           |               | 
+(6 rows)
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
+-----------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
+           | infinity          | infinity      |                   |                | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
+ @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
+ @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
+           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
+ -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
+(7 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..d00423946d 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,6 +1591,49 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+--order by.
+SELECT  x
+        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--no order by.
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 87c1aee379..236683e5ab 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3

From d6d5149d7395ee454eea3e0f630cb56556ae4681 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 15:34:33 +0530
Subject: [PATCH v27 5/8] Use integer overflow checking routines to add and
 subtract finite intervals

Use pg_add/sub_s32/64_overflow() routines in finite_interval_pl() and
finite_interval_mi() instead of adding overflow checks in those
functions.

Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c      | 121 +++++++++++--------------
 src/test/regress/expected/interval.out |  11 +++
 src/test/regress/expected/window.out   |  54 ++++-------
 src/test/regress/sql/interval.sql      |   3 +
 src/test/regress/sql/window.sql        |  22 ++---
 5 files changed, 95 insertions(+), 116 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 450b547036..4b35ee0bdf 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -99,6 +99,8 @@ static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 static void interval_um_internal(Interval *interval, Interval *result);
 static void finite_interval_pl(Interval *result, Interval *span1,
 							   Interval *span2);
+static void finite_interval_mi(Interval *result, Interval *span1,
+							   Interval *span2);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -3502,34 +3504,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-	{
-		result->month = span1->month - span2->month;
-		/* overflow check copied from int4mi */
-		if (!SAMESIGN(span1->month, span2->month) &&
-			!SAMESIGN(result->month, span1->month))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->day = span1->day - span2->day;
-		if (!SAMESIGN(span1->day, span2->day) &&
-			!SAMESIGN(result->day, span1->day))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		result->time = span1->time - span2->time;
-		if (!SAMESIGN(span1->time, span2->time) &&
-			!SAMESIGN(result->time, span1->time))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-
-		if (INTERVAL_NOT_FINITE(result))
-			ereport(ERROR,
-					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
-	}
+		finite_interval_mi(result, span1, span2);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3869,11 +3844,18 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Function to add two finite intervals.
+ * Functions to add or subtract two finite intervals.
+ *
+ * We handle non-finite intervals in different ways when accumulating/discarding
+ * intervals and in actual mathematical operations respectively. But the
+ * addition or subtraction of finite intervals have same implementation
+ * respectively in both these cases.
+ *
+ * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
+ * to pass either of span1 or span2 as a result pointer. In such a case result
+ * will overwrite the given value.
  *
- * We handle non-finite intervals in different ways when accumulating intervals
- * and adding two intervals respectively. But the addition of finite interval
- * has same implementation in both these cases.
+ * If the result is not a valid interval, the function throws an error.
  */
 static void
 finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
@@ -3881,24 +3863,44 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
@@ -3915,9 +3917,6 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-
-	Interval	temp;
-
 	/* Count -infinity inputs separately from all else */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
@@ -3932,8 +3931,7 @@ do_interval_accum(IntervalAggState *state, Interval *newval)
 		return;
 	}
 
-	memcpy(&temp, &state->sumX, sizeof(Interval));
-	finite_interval_pl(&state->sumX, &temp, newval);
+	finite_interval_pl(&state->sumX, &state->sumX, newval);
 	state->N++;
 }
 
@@ -3959,6 +3957,9 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 
 /*
  * Combine function for interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in the
+ * first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3972,9 +3973,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	if (state2 == NULL)
 		PG_RETURN_POINTER(state1);
 
-	/* manually copy all fields from state2 to state1 */
 	if (state1 == NULL)
 	{
+		/* manually copy all fields from state2 to state1 */
 		state1 = makeIntervalAggState(fcinfo);
 
 		state1->N = state2->N;
@@ -3992,14 +3993,9 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	state1->pInfcount += state2->pInfcount;
 	state1->nInfcount += state2->nInfcount;
 
+	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-	{
-		Interval	temp;
-
-		/* Accumulate interval values */
-		memcpy(&temp, &state1->sumX, sizeof(Interval));
-		finite_interval_pl(&state1->sumX, &temp, &state2->sumX);
-	}
+		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4025,24 +4021,15 @@ do_interval_discard(IntervalAggState *state, Interval *newval)
 	}
 
 	/* Handle to be discarded finite value. */
+	state->N--;
 	if (state->N > 0)
-	{
-		Interval	temp;
-		Interval	neg_val;
-
-		neg_val.day = -newval->day;
-		neg_val.month = -newval->month;
-		neg_val.time = -newval->time;
-
-		memcpy(&temp, &state->sumX, sizeof(Interval));
-		finite_interval_pl(&state->sumX, &temp, &neg_val);
-	}
+		finite_interval_mi(&state->sumX, &state->sumX, newval);
 	else
 	{
 		/* All values discarded, reset the state */
+		Assert(state->N == 0);
 		memset(&state->sumX, 0, sizeof(state->sumX));
 	}
-	state->N--;
 }
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 135d683285..8bd72f60b0 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -347,6 +347,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 45262924cd..63f36e069e 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4375,51 +4375,37 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-     x     | curr_next_avg | prev1_curr_sum 
------------+---------------+----------------
- -infinity | -infinity     | -infinity
- @ 6 days  | infinity      | -infinity
- infinity  | infinity      | infinity
- infinity  | infinity      | infinity
-           |               | infinity
-           |               | 
-(6 rows)
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-     x     |   curr_next_avg   | curr_next_sum |  prev1_curr_avg   | prev1_curr_sum | prev1_next2_avg | prev1_next2_sum 
------------+-------------------+---------------+-------------------+----------------+-----------------+-----------------
-           | infinity          | infinity      |                   |                | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- infinity  | infinity          | infinity      | infinity          | infinity       | infinity        | infinity
- @ 6 days  | @ 6 days 12 hours | @ 13 days     | infinity          | infinity       | infinity        | infinity
- @ 7 days  | @ 7 days          | @ 7 days      | @ 6 days 12 hours | @ 13 days      | -infinity       | -infinity
-           | -infinity         | -infinity     | @ 7 days          | @ 7 days       | -infinity       | -infinity
- -infinity | -infinity         | -infinity     | -infinity         | -infinity      | -infinity       | -infinity
-(7 rows)
+                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
+----------------------------------------------+-------------------+-------------------+---------------+----------------
+                                              | infinity          |                   | infinity      | 
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
+ infinity                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
 
 --should fail.
 SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 912803a1b0..414c12be1c 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -99,6 +99,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index d00423946d..6dd9885949 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1591,28 +1591,20 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
---order by.
-SELECT  x
-        ,avg(x) OVER(ORDER BY x ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ORDER BY x ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-FROM (VALUES (NULL::interval),
-               ('infinity'::interval),
-               ('infinity'::timestamptz - now()),
-               ('6 days'::interval),
-               (NULL::interval),
-               ('-infinity'::interval)) v(x);
-
---no order by.
+-- window function over interval, infinity and extreme values test the
+-- behaviour of accumulation and elimination of these values as the window
+-- slides.
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
         ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_avg
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING ) as prev1_next2_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
+               ('2147483647 days 2147483646 months'), -- extreme interval value
                ('infinity'::timestamptz - now()),
+               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
-- 
2.35.3

From 905397e5642dfbdd61c6c795ed6e8ef15ce31be4 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 1 Apr 2023 10:22:53 -0400
Subject: [PATCH v27 1/8] Check for overflow in make_interval

---
 src/backend/utils/adt/timestamp.c      | 39 ++++++++++++++++++--------
 src/include/datatype/timestamp.h       |  1 +
 src/test/regress/expected/interval.out | 27 ++++++++++++++++++
 src/test/regress/sql/interval.sql      | 15 ++++++++++
 4 files changed, 71 insertions(+), 11 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index e172e90614..647b97aca6 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -1509,24 +1509,41 @@ make_interval(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	/*
-	 * Reject out-of-range inputs.  We really ought to check the integer
-	 * inputs as well, but it's not entirely clear what limits to apply.
+	 * Reject out-of-range inputs.  We reject any input values that cause
+	 * integer overflow of the corresponding interval fields.
 	 */
 	if (isinf(secs) || isnan(secs))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+		goto out_of_range;
 
 	result = (Interval *) palloc(sizeof(Interval));
-	result->month = years * MONTHS_PER_YEAR + months;
-	result->day = weeks * 7 + days;
 
-	secs = rint(secs * USECS_PER_SEC);
-	result->time = hours * ((int64) SECS_PER_HOUR * USECS_PER_SEC) +
-		mins * ((int64) SECS_PER_MINUTE * USECS_PER_SEC) +
-		(int64) secs;
+	/* years and months -> months */
+	if (pg_mul_s32_overflow(years, MONTHS_PER_YEAR, &result->month) ||
+		pg_add_s32_overflow(result->month, months, &result->month))
+		goto out_of_range;
+
+	/* weeks and days -> days */
+	if (pg_mul_s32_overflow(weeks, DAYS_PER_WEEK, &result->day) ||
+		pg_add_s32_overflow(result->day, days, &result->day))
+		goto out_of_range;
+
+	/* hours and mins -> usecs (cannot overflow 64-bit) */
+	result->time = hours * USECS_PER_HOUR + mins * USECS_PER_MINUTE;
+
+	/* secs -> usecs */
+	secs = rint(float8_mul(secs, USECS_PER_SEC));
+	if (!FLOAT8_FITS_IN_INT64(secs) ||
+		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
+		goto out_of_range;
 
 	PG_RETURN_INTERVAL_P(result);
+
+out_of_range:
+	ereport(ERROR,
+			errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+			errmsg("interval out of range"));
+
+	PG_RETURN_NULL();			/* keep compiler quiet */
 }
 
 /* EncodeSpecialTimestamp()
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index ab8ccf89ca..1a6390585c 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -114,6 +114,7 @@ struct pg_itm_in
  *	30 days.
  */
 #define DAYS_PER_MONTH	30		/* assumes exactly 30 days per month */
+#define DAYS_PER_WEEK	7
 #define HOURS_PER_DAY	24		/* assume no daylight savings time changes */
 
 /*
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index c0ca8e041b..75d19d6594 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -1587,6 +1587,33 @@ select interval '-2147483648 months -2147483648 days -9223372036854775808 micros
 ERROR:  interval field value out of range: "-2147483648 months -2147483648 days -9223372036854775808 microseconds ago"
 LINE 1: select interval '-2147483648 months -2147483648 days -922337...
                         ^
+-- overflowing using make_interval
+select make_interval(years := 178956971);
+ERROR:  interval out of range
+select make_interval(years := -178956971);
+ERROR:  interval out of range
+select make_interval(years := 1, months := 2147483647);
+ERROR:  interval out of range
+select make_interval(years := -1, months := -2147483648);
+ERROR:  interval out of range
+select make_interval(weeks := 306783379);
+ERROR:  interval out of range
+select make_interval(weeks := -306783379);
+ERROR:  interval out of range
+select make_interval(weeks := 1, days := 2147483647);
+ERROR:  interval out of range
+select make_interval(weeks := -1, days := -2147483648);
+ERROR:  interval out of range
+select make_interval(secs := 1e308);
+ERROR:  value out of range: overflow
+select make_interval(secs := 1e18);
+ERROR:  interval out of range
+select make_interval(secs := -1e18);
+ERROR:  interval out of range
+select make_interval(mins := 1, secs := 9223372036800.0);
+ERROR:  interval out of range
+select make_interval(mins := -1, secs := -9223372036800.0);
+ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 038fc508d0..a0a373f08b 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -511,6 +511,21 @@ select interval '-2147483648 days ago';
 select interval '-9223372036854775808 microseconds ago';
 select interval '-2147483648 months -2147483648 days -9223372036854775808 microseconds ago';
 
+-- overflowing using make_interval
+select make_interval(years := 178956971);
+select make_interval(years := -178956971);
+select make_interval(years := 1, months := 2147483647);
+select make_interval(years := -1, months := -2147483648);
+select make_interval(weeks := 306783379);
+select make_interval(weeks := -306783379);
+select make_interval(weeks := 1, days := 2147483647);
+select make_interval(weeks := -1, days := -2147483648);
+select make_interval(secs := 1e308);
+select make_interval(secs := 1e18);
+select make_interval(secs := -1e18);
+select make_interval(mins := 1, secs := 9223372036800.0);
+select make_interval(mins := -1, secs := -9223372036800.0);
+
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
 select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-- 
2.35.3

From be85f1810ccba0988c68a875c5debff630eabf02 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 21 Sep 2023 16:52:30 +0530
Subject: [PATCH v27 6/8] Implement serialization functions for interval
 aggregate state

Now that interval aggregates use transition state which of date type Internal,
parallel aggregates require these separate functions.

Jian He and Ashutosh Bapat
---
 src/backend/utils/adt/timestamp.c    | 84 +++++++++++++++++++++++++++-
 src/include/catalog/pg_aggregate.dat |  4 ++
 src/include/catalog/pg_proc.dat      |  6 ++
 3 files changed, 92 insertions(+), 2 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 4b35ee0bdf..0b385fd72c 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3821,8 +3821,12 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * Prepare state data for an interval aggregate function that needs to compute
- * sum and count.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
  */
 static IntervalAggState *
 makeIntervalAggState(FunctionCallInfo fcinfo)
@@ -4000,6 +4004,82 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_serialize(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
+
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	/* TODO: Handle NULL inputs? */
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+	pq_begintypsend(&buf);
+	/* N */
+	pq_sendint64(&buf, state->N);
+	/* Finite interval value */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
+	result = pq_endtypsend(&buf);
+	PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
+Datum
+interval_avg_deserialize(PG_FUNCTION_ARGS)
+{
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	sstate = PG_GETARG_BYTEA_PP(0);
+
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
+
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
+
+	/* Interval struct elements, one by one. */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
+	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
+}
+
 /*
  * Remove the given interval value from the aggregated state.
  */
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index e2087d7be1..0e62c3f7a6 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -45,6 +45,8 @@
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
 { aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
@@ -75,6 +77,8 @@
   aggtranstype => 'money', aggmtranstype => 'money' },
 { aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
   aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
   aggmtranstype => 'internal', aggtransspace => '128',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 791359a6e0..7d66de5043 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4928,6 +4928,12 @@
   proname => 'interval_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
   prosrc => 'interval_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
   proname => 'interval_avg', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
-- 
2.35.3

From 784c97837355bedcf84f2aed9d2c608773a81d3a Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Thu, 28 Sep 2023 14:54:02 +0100
Subject: [PATCH v27 7/8] Code review of infinite interval support.

---
 doc/src/sgml/func.sgml                    |   5 +-
 src/backend/utils/adt/date.c              |  27 +-
 src/backend/utils/adt/datetime.c          |   4 +-
 src/backend/utils/adt/selfuncs.c          |  16 +-
 src/backend/utils/adt/timestamp.c         | 366 +++++++++----------
 src/include/catalog/pg_aggregate.dat      |  11 +-
 src/include/catalog/pg_proc.dat           |   6 +-
 src/include/datatype/timestamp.h          |  24 +-
 src/include/utils/timestamp.h             |   3 -
 src/test/regress/expected/interval.out    | 375 ++++++++------------
 src/test/regress/expected/timestamp.out   |   8 +-
 src/test/regress/expected/timestamptz.out |   8 +-
 src/test/regress/expected/window.out      | 406 +++++++++++++++++++---
 src/test/regress/sql/interval.sql         | 131 +++----
 src/test/regress/sql/window.sql           |  93 ++++-
 15 files changed, 912 insertions(+), 571 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index c4f09df544..682e3713c6 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10435,7 +10435,10 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
      <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
-     for all types and <literal>hour</literal> and <literal>day</literal> just for <type>interval</type>).
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index ad97f07601..cafe3abe21 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2050,8 +2051,6 @@ time_mi_time(PG_FUNCTION_ARGS)
 	result->day = 0;
 	result->time = time1 - time2;
 
-	Assert(!INTERVAL_NOT_FINITE(result));
-
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2116,7 +2115,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2126,13 +2126,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2666,7 +2667,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2676,13 +2678,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 73dadb747c..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3613,9 +3613,9 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 							return DTERR_BAD_FORMAT;
 
 						/*
-						 * infinity can not be followed by anything else. We
+						 * Infinity cannot be followed by anything else. We
 						 * could allow "ago" to reverse the sign of infinity
-						 * but that signed infinity is more intuitive.
+						 * but using signed infinity is more intuitive.
 						 */
 						if (i != nf - 1)
 							return DTERR_BAD_FORMAT;
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 6e87173846..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4795,7 +4795,21 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 		case DATEOID:
 			return date2timestamp_no_overflow(DatumGetDateADT(value));
 		case INTERVALOID:
-			return interval2timestamp_no_overflow(DatumGetIntervalP(value));
+			{
+				Interval   *interval = DatumGetIntervalP(value);
+
+				/*
+				 * Convert the month part of Interval to days using assumed
+				 * average month length of 365.25/12.0 days.  Not too
+				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
+				 */
+				return interval->time + interval->day * (double) USECS_PER_DAY +
+					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
+			}
 		case TIMEOID:
 			return DatumGetTimeADT(value);
 		case TIMETZOID:
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 0b385fd72c..23d43094e8 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -18,7 +18,6 @@
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>
-#include <float.h>
 #include <sys/time.h>
 
 #include "access/xact.h"
@@ -74,16 +73,16 @@ typedef struct
 } generate_series_timestamptz_fctx;
 
 /*
- * The transition datatype for interval aggregates is declared as Internal. It's
- * a pointer to a IntervalAggState allocated in the aggregate context.
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
  */
 typedef struct IntervalAggState
 {
-	int64		N;				/* count of processed intervals */
-	Interval	sumX;			/* sum of processed intervals */
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
 	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
-	int64		pInfcount;		/* count of +Inf values */
-	int64		nInfcount;		/* count of -Inf values */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
 } IntervalAggState;
 
 #define IA_TOTAL_COUNT(ia) \
@@ -96,11 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
-static void interval_um_internal(Interval *interval, Interval *result);
-static void finite_interval_pl(Interval *result, Interval *span1,
-							   Interval *span2);
-static void finite_interval_mi(Interval *result, Interval *span1,
-							   Interval *span2);
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -1604,8 +1604,8 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
-void
-EncodeSpecialInterval(Interval *interval, char *str)
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
 {
 	if (INTERVAL_IS_NOBEGIN(interval))
 		strcpy(str, EARLY);
@@ -2101,6 +2101,13 @@ itm2interval(struct pg_itm *itm, Interval *span)
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2112,8 +2119,6 @@ itmin2interval(struct pg_itm_in *itm_in, Interval *span)
 	span->month = (int32) total_months;
 	span->day = itm_in->tm_mday;
 	span->time = itm_in->tm_usec;
-	if (INTERVAL_NOT_FINITE(span))
-		return -1;
 	return 0;
 }
 
@@ -2280,29 +2285,6 @@ timestamp_fastcmp(Datum x, Datum y, SortSupport ssup)
 }
 #endif
 
-double
-interval2timestamp_no_overflow(Interval *interval)
-{
-	double		result;
-
-	if (INTERVAL_IS_NOBEGIN(interval))
-		result = -DBL_MAX;
-	else if (INTERVAL_IS_NOEND(interval))
-		result = DBL_MAX;
-	else
-	{
-		/*
-		 * Convert the month part of Interval to days using assumed average
-		 * month length of 365.25/12.0 days.  Not too accurate, but plenty
-		 * good enough for our purposes.
-		 */
-		return interval->time + interval->day * (double) USECS_PER_DAY +
-			interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
-	}
-
-	return result;
-}
-
 Datum
 timestamp_sortsupport(PG_FUNCTION_ARGS)
 {
@@ -2526,6 +2508,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2801,14 +2792,14 @@ timestamp_mi(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -2817,7 +2808,7 @@ timestamp_mi(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -3068,16 +3059,16 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Timestamp	result;
 
 	/*
-	 * Adding two infinites with the same sign results in an infinite
-	 * timestamp with the same sign. Adding two infintes with different signs
-	 * results in an error.
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span))
 	{
 		if (TIMESTAMP_IS_NOEND(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOBEGIN(result);
 	}
@@ -3086,7 +3077,7 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOBEGIN(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOEND(result);
 	}
@@ -3197,16 +3188,16 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	int			tz;
 
 	/*
-	 * Adding two infinites with the same sign results in an infinite
-	 * timestamp with the same sign. Adding two infintes with different signs
-	 * results in an error.
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span))
 	{
 		if (TIMESTAMP_IS_NOEND(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOBEGIN(result);
 	}
@@ -3215,7 +3206,7 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 		if (TIMESTAMP_IS_NOBEGIN(timestamp))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range")));
+					 errmsg("timestamp out of range")));
 		else
 			TIMESTAMP_NOEND(result);
 	}
@@ -3362,16 +3353,12 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 
 /* Negates the given interval */
 static void
-interval_um_internal(Interval *interval, Interval *result)
+interval_um_internal(const Interval *interval, Interval *result)
 {
 	if (INTERVAL_IS_NOBEGIN(interval))
 		INTERVAL_NOEND(result);
 	else if (INTERVAL_IS_NOEND(interval))
 		INTERVAL_NOBEGIN(result);
-	else if (interval->time == PG_INT64_MIN || interval->day == PG_INT32_MIN || interval->month == PG_INT32_MIN)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
 	else
 	{
 		result->time = -interval->time;
@@ -3438,8 +3425,8 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	/*
 	 * Adding two infinite intervals with the same signs results in an
-	 * infinite interval with the same sign. Adding two infinte intervals with
-	 * different signs results in an error.
+	 * infinite interval with the same sign. Adding two infinite intervals
+	 * with different signs results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span1))
 	{
@@ -3462,7 +3449,7 @@ interval_pl(PG_FUNCTION_ARGS)
 	else if (INTERVAL_NOT_FINITE(span2))
 		memcpy(result, span2, sizeof(Interval));
 	else
-		finite_interval_pl(result, span1, span2);
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3479,7 +3466,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite intervals with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte intervals with the same sign results in an error.
+	 * two infinite intervals with the same sign results in an error.
 	 */
 	if (INTERVAL_IS_NOBEGIN(span1))
 	{
@@ -3504,7 +3491,7 @@ interval_mi(PG_FUNCTION_ARGS)
 	else if (INTERVAL_IS_NOEND(span2))
 		INTERVAL_NOBEGIN(result);
 	else
-		finite_interval_mi(result, span1, span2);
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3552,13 +3539,11 @@ interval_mul(PG_FUNCTION_ARGS)
 	}
 	else if (isinf(factor))
 	{
-		Interval	zero;
 		int			factor_sign,
 					result_sign;
 
 		factor_sign = factor >= 0.0 ? 1 : -1;
-		memset(&zero, 0, sizeof(zero));
-		result_sign = interval_cmp_internal(span, &zero) * factor_sign;
+		result_sign = interval_sign(span) * factor_sign;
 
 		if (result_sign == 0)
 			ereport(ERROR,
@@ -3740,11 +3725,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3767,11 +3762,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3798,11 +3803,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3848,21 +3863,13 @@ makeIntervalAggState(FunctionCallInfo fcinfo)
 }
 
 /*
- * Functions to add or subtract two finite intervals.
+ * Functions to add or subtract finite intervals.
  *
- * We handle non-finite intervals in different ways when accumulating/discarding
- * intervals and in actual mathematical operations respectively. But the
- * addition or subtraction of finite intervals have same implementation
- * respectively in both these cases.
- *
- * Addition/Subtraction of span1 and span2 is stored in the result. It is fine
- * to pass either of span1 or span2 as a result pointer. In such a case result
- * will overwrite the given value.
- *
- * If the result is not a valid interval, the function throws an error.
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
  */
 static void
-finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
 {
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
@@ -3889,7 +3896,7 @@ finite_interval_pl(Interval *result, Interval *span1, Interval *span2)
 }
 
 static void
-finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
 {
 	Assert(!INTERVAL_NOT_FINITE(span1));
 	Assert(!INTERVAL_NOT_FINITE(span2));
@@ -3921,26 +3928,56 @@ finite_interval_mi(Interval *result, Interval *span1, Interval *span2)
 static void
 do_interval_accum(IntervalAggState *state, Interval *newval)
 {
-	/* Count -infinity inputs separately from all else */
+	/* Infinite inputs are counted separately, and do not affect "N" */
 	if (INTERVAL_IS_NOBEGIN(newval))
 	{
 		state->nInfcount++;
 		return;
 	}
 
-	/* Count infinity inputs separately from all else */
 	if (INTERVAL_IS_NOEND(newval))
 	{
 		state->pInfcount++;
 		return;
 	}
 
-	finite_interval_pl(&state->sumX, &state->sumX, newval);
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
 	state->N++;
 }
 
 /*
- * Transition function for interval aggregates.
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle to be discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
  */
 Datum
 interval_avg_accum(PG_FUNCTION_ARGS)
@@ -3960,10 +3997,10 @@ interval_avg_accum(PG_FUNCTION_ARGS)
 }
 
 /*
- * Combine function for interval aggregates.
+ * Combine function for sum() and avg() interval aggregates.
  *
- * Combine the given internal aggregate states and place the combination in the
- * first argument.
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
  */
 Datum
 interval_avg_combine(PG_FUNCTION_ARGS)
@@ -3999,7 +4036,7 @@ interval_avg_combine(PG_FUNCTION_ARGS)
 
 	/* Accumulate finite interval values, if any. */
 	if (state2->N > 0)
-		finite_interval_pl(&state1->sumX, &state1->sumX, &state2->sumX);
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
 
 	PG_RETURN_POINTER(state1);
 }
@@ -4019,20 +4056,26 @@ interval_avg_serialize(PG_FUNCTION_ARGS)
 	if (!AggCheckCallContext(fcinfo, NULL))
 		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	/* TODO: Handle NULL inputs? */
 	state = (IntervalAggState *) PG_GETARG_POINTER(0);
+
 	pq_begintypsend(&buf);
+
 	/* N */
 	pq_sendint64(&buf, state->N);
-	/* Finite interval value */
+
+	/* sumX */
 	pq_sendint64(&buf, state->sumX.time);
 	pq_sendint32(&buf, state->sumX.day);
 	pq_sendint32(&buf, state->sumX.month);
+
 	/* pInfcount */
 	pq_sendint64(&buf, state->pInfcount);
+
 	/* nInfcount */
 	pq_sendint64(&buf, state->nInfcount);
+
 	result = pq_endtypsend(&buf);
+
 	PG_RETURN_BYTEA_P(result);
 }
 
@@ -4064,10 +4107,10 @@ interval_avg_deserialize(PG_FUNCTION_ARGS)
 	/* N */
 	result->N = pq_getmsgint64(&buf);
 
-	/* Interval struct elements, one by one. */
+	/* sumX */
 	result->sumX.time = pq_getmsgint64(&buf);
-	result->sumX.day = pq_getmsgint(&buf, sizeof(result->sumX.day));
-	result->sumX.month = pq_getmsgint(&buf, sizeof(result->sumX.month));
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
 
 	/* pInfcount */
 	result->pInfcount = pq_getmsgint64(&buf);
@@ -4081,42 +4124,10 @@ interval_avg_deserialize(PG_FUNCTION_ARGS)
 }
 
 /*
- * Remove the given interval value from the aggregated state.
- */
-static void
-do_interval_discard(IntervalAggState *state, Interval *newval)
-{
-	/* Count -infinity inputs separately from all else */
-	if (INTERVAL_IS_NOBEGIN(newval))
-	{
-		state->nInfcount--;
-		return;
-	}
-
-	/* Count infinity inputs separately from all else */
-	if (INTERVAL_IS_NOEND(newval))
-	{
-		state->pInfcount--;
-		return;
-	}
-
-	/* Handle to be discarded finite value. */
-	state->N--;
-	if (state->N > 0)
-		finite_interval_mi(&state->sumX, &state->sumX, newval);
-	else
-	{
-		/* All values discarded, reset the state */
-		Assert(state->N == 0);
-		memset(&state->sumX, 0, sizeof(state->sumX));
-	}
-}
-
-/*
- * Generic inverse transition function for interval aggregates
+ * Inverse transition function for sum() and avg() interval aggregates.
  */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
 	IntervalAggState *state;
 
@@ -4124,7 +4135,7 @@ interval_accum_inv(PG_FUNCTION_ARGS)
 
 	/* Should not get here with no state */
 	if (state == NULL)
-		elog(ERROR, "interval_accum_inv called with NULL state");
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
 
 	if (!PG_ARGISNULL(1))
 		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
@@ -4137,38 +4148,39 @@ Datum
 interval_avg(PG_FUNCTION_ARGS)
 {
 	IntervalAggState *state;
-	double		N_datum;
-	Interval   *sumX;
 
-	sumX = (Interval *) palloc(sizeof(Interval));
 	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
+	/* If there were no non-null inputs, return NULL */
 	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	/* adding plus and minus infinities gives error */
-	if (state->pInfcount > 0 && state->nInfcount > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range.")));
-
-	if (state->pInfcount > 0)
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
 	{
-		INTERVAL_NOEND(sumX);
-		PG_RETURN_INTERVAL_P(sumX);
-	}
+		Interval   *result;
 
-	if (state->nInfcount > 0)
-	{
-		INTERVAL_NOBEGIN(sumX);
-		PG_RETURN_INTERVAL_P(sumX);
-	}
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
 
-	N_datum = (double) state->N;
-	sumX = &state->sumX;
+		PG_RETURN_INTERVAL_P(result);
+	}
 
-	PG_RETURN_DATUM(DirectFunctionCall2(interval_div, IntervalPGetDatum(sumX),
-										Float8GetDatum(N_datum)));
+	return DirectFunctionCall2(interval_div,
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
 /* sum(interval) aggregate final function */
@@ -4178,33 +4190,31 @@ interval_sum(PG_FUNCTION_ARGS)
 	IntervalAggState *state;
 	Interval   *result;
 
-	result = (Interval *) palloc(sizeof(Interval));
-
 	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
 	/* If there were no non-null inputs, return NULL */
 	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
-	/* adding plus and minus interval infinities is not possible */
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
 	if (state->pInfcount > 0 && state->nInfcount > 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range.")));
 
+	result = (Interval *) palloc(sizeof(Interval));
+
 	if (state->pInfcount > 0)
-	{
 		INTERVAL_NOEND(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
-
-	if (state->nInfcount > 0)
-	{
+	else if (state->nInfcount > 0)
 		INTERVAL_NOBEGIN(result);
-		PG_RETURN_INTERVAL_P(result);
-	}
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
 
-	memcpy(result, &state->sumX, sizeof(Interval));
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -4234,14 +4244,14 @@ timestamp_age(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -4250,7 +4260,7 @@ timestamp_age(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -4381,14 +4391,14 @@ timestamptz_age(PG_FUNCTION_ARGS)
 	/*
 	 * Subtracting two infinite timestamps with different signs results in an
 	 * infinite interval with the same sign as the left operand. Subtracting
-	 * two infinte timestamps with the same sign results in an error.
+	 * two infinite timestamps with the same sign results in an error.
 	 */
 	if (TIMESTAMP_IS_NOBEGIN(dt1))
 	{
 		if (TIMESTAMP_IS_NOBEGIN(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOBEGIN(result);
 	}
@@ -4397,7 +4407,7 @@ timestamptz_age(PG_FUNCTION_ARGS)
 		if (TIMESTAMP_IS_NOEND(dt2))
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("timestamp out of range")));
+					 errmsg("interval out of range")));
 		else
 			INTERVAL_NOEND(result);
 	}
@@ -5829,17 +5839,16 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 /*
  * NonFiniteIntervalPart
  *
- *	Used by interval_part when extracting from infinite
- *	interval.  Returns +/-Infinity if that is the appropriate result,
- *	otherwise returns zero (which should be taken as meaning to return NULL).
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
  *
  *	Errors thrown here for invalid units should exactly match those that
  *	would be thrown in the calling functions, else there will be unexpected
  *	discrepancies between finite- and infinite-input cases.
  */
 static float8
-NonFiniteIntervalPart(int type, int unit, char *lowunits,
-					  bool isNegative, bool isTz)
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
 {
 	if ((type != UNITS) && (type != RESERV))
 		ereport(ERROR,
@@ -5906,8 +5915,7 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (INTERVAL_NOT_FINITE(interval))
 	{
 		double		r = NonFiniteIntervalPart(type, val, lowunits,
-											  INTERVAL_IS_NOBEGIN(interval),
-											  false);
+											  INTERVAL_IS_NOBEGIN(interval));
 
 		if (r != 0.0)
 		{
@@ -6453,7 +6461,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -6476,7 +6483,7 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
@@ -6539,7 +6546,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -6563,7 +6569,7 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 0e62c3f7a6..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -47,11 +47,9 @@
   aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
   aggserialfn => 'interval_avg_serialize',
   aggdeserialfn => 'interval_avg_deserialize',
-  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
   aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
-  aggmtranstype => 'internal', aggtransspace => '128',
-  aggmtransspace => '128'
-},
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -79,10 +77,9 @@
   aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
   aggserialfn => 'interval_avg_serialize',
   aggdeserialfn => 'interval_avg_deserialize',
-  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_accum_inv',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
   aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
-  aggmtranstype => 'internal', aggtransspace => '128',
-  aggmtransspace => '128'},
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 7d66de5043..455ed16c79 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4925,9 +4925,9 @@
   prorettype => 'internal', proargtypes => 'internal internal',
   prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', proisstrict => 'f',
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
   prorettype => 'internal', proargtypes => 'internal interval',
-  prosrc => 'interval_accum_inv' },
+  prosrc => 'interval_avg_accum_inv' },
 { oid => '3813', descr => 'aggregate serial function',
   proname => 'interval_avg_serialize', prorettype => 'bytea',
   proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
@@ -4935,7 +4935,7 @@
   proname => 'interval_avg_deserialize', prorettype => 'internal',
   proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
   proargtypes => 'internal', prosrc => 'interval_avg' },
 { oid => '8069', descr => 'aggregate final function',
   proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index f9bd30d225..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,23 +168,29 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
 #define INTERVAL_NOBEGIN(i)	\
 	do {	\
-		(i->time) = PG_INT64_MIN;	\
-		(i->day) = PG_INT32_MIN;	\
-		(i->month) = PG_INT32_MIN;	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
 	} while (0)
 
-#define INTERVAL_IS_NOBEGIN(i) ((i->month) == PG_INT32_MIN)
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
 
 #define INTERVAL_NOEND(i)	\
 	do {	\
-		(i->time) = PG_INT64_MAX;	\
-		(i->day) = PG_INT32_MAX;	\
-		(i->month) = PG_INT32_MAX;	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
 	} while (0)
 
-#define INTERVAL_IS_NOEND(i) ((i->month) == PG_INT32_MAX)
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
 
 #define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index fe713fb6dd..c4dd96c8c9 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -118,7 +118,6 @@ extern int	timestamp2tm(Timestamp dt, int *tzp, struct pg_tm *tm,
 						 fsec_t *fsec, const char **tzn, pg_tz *attimezone);
 extern void dt2time(Timestamp jd, int *hour, int *min, int *sec, fsec_t *fsec);
 
-extern void EncodeSpecialInterval(Interval *interval, char *str);
 extern void interval2itm(Interval span, struct pg_itm *itm);
 extern int	itm2interval(struct pg_itm *itm, Interval *span);
 extern int	itmin2interval(struct pg_itm_in *itm_in, Interval *span);
@@ -128,8 +127,6 @@ extern void GetEpochTime(struct pg_tm *tm);
 
 extern int	timestamp_cmp_internal(Timestamp dt1, Timestamp dt2);
 
-extern double interval2timestamp_no_overflow(Interval *interval);
-
 /* timestamp comparison works for timestamptz also */
 #define timestamptz_cmp_internal(dt1,dt2)	timestamp_cmp_internal(dt1, dt2)
 
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 8bd72f60b0..00cd3e84f1 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -284,11 +284,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483646 months'),
-  ('2147483647 days -2147483647 months'),
+  ('2147483647 days 2147483647 months'),
+  ('2147483647 days -2147483648 months'),
   ('1 year'),
-  ('-2147483648 days 2147483646 months'),
-  ('-2147483648 days -2147483647 months');
+  ('-2147483648 days 2147483647 months'),
+  ('-2147483648 days -2147483648 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 ERROR:  interval field value out of range: "2147483648 days"
@@ -315,16 +315,16 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
                     f1                     |                    f1                     
 -------------------------------------------+-------------------------------------------
- -178956970 years -7 mons +2147483647 days | -178956970 years -7 mons -2147483648 days
- 1 year                                    | -178956970 years -7 mons -2147483648 days
- 1 year                                    | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons -2147483648 days
- 178956970 years 6 mons -2147483648 days   | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons -2147483648 days   | 1 year
- 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons -2147483648 days
- 178956970 years 6 mons 2147483647 days    | -178956970 years -7 mons +2147483647 days
- 178956970 years 6 mons 2147483647 days    | 1 year
- 178956970 years 6 mons 2147483647 days    | 178956970 years 6 mons -2147483648 days
+ -178956970 years -8 mons +2147483647 days | -178956970 years -8 mons -2147483648 days
+ 1 year                                    | -178956970 years -8 mons -2147483648 days
+ 1 year                                    | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons -2147483648 days
+ 178956970 years 7 mons -2147483648 days   | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons -2147483648 days   | 1 year
+ 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons -2147483648 days
+ 178956970 years 7 mons 2147483647 days    | -178956970 years -8 mons +2147483647 days
+ 178956970 years 7 mons 2147483647 days    | 1 year
+ 178956970 years 7 mons 2147483647 days    | 178956970 years 7 mons -2147483648 days
 (10 rows)
 
 CREATE INDEX ON INTERVAL_TBL_OF USING btree (f1);
@@ -339,11 +339,11 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
                     f1                     
 -------------------------------------------
- -178956970 years -7 mons -2147483648 days
- -178956970 years -7 mons +2147483647 days
+ -178956970 years -8 mons -2147483648 days
+ -178956970 years -8 mons +2147483647 days
  1 year
- 178956970 years 6 mons -2147483648 days
- 178956970 years 6 mons 2147483647 days
+ 178956970 years 7 mons -2147483648 days
+ 178956970 years 7 mons 2147483647 days
 (5 rows)
 
 RESET enable_seqscan;
@@ -485,9 +485,7 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
 ERROR:  interval out of range
-SELECT justify_days(interval '2147483646 months 30 days');
-ERROR:  interval out of range
-SELECT justify_days(interval '2147483646 months 60 days');
+SELECT justify_days(interval '2147483647 months 30 days');
 ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@@ -508,29 +506,25 @@ SELECT justify_interval(interval '-2147483648 days -24 hrs');
  @ 5965232 years 4 mons 9 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483646 months 30 days');
-ERROR:  interval out of range
-SELECT justify_interval(interval '2147483646 months 60 days');
-ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months -60 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
 ERROR:  interval out of range
-SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
          justify_interval         
 ----------------------------------
- @ 178956970 years 6 mons 29 days
+ @ 178956970 years 7 mons 29 days
 (1 row)
 
-SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
            justify_interval           
 --------------------------------------
- @ 178956970 years 7 mons 29 days ago
+ @ 178956970 years 8 mons 29 days ago
 (1 row)
 
-SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
 ERROR:  interval out of range
-SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
 ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -1882,233 +1876,144 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
--- infinite intervals
-SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
-ERROR:  interval out of range
-LINE 1: SELECT interval '-2147483648 months -2147483648 days -922337...
-                        ^
-SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
-ERROR:  interval out of range
-LINE 1: SELECT interval '2147483647 months 2147483647 days 922337203...
-                        ^
-CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
-INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
-SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
-            i            | isfinite 
--------------------------+----------
- infinity                | f
- -infinity               | f
- @ 1 year 2 days 3 hours | t
-(3 rows)
-
-SELECT date '1995-08-06' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date '1995-08-06' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT date '1995-08-06' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT date '1995-08-06' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT date 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT date '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT date '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
 (1 row)
 
-SELECT date 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT date 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
 (1 row)
 
-SELECT date '-infinity' - interval 'infinity';
- ?column?  
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
 -----------
  -infinity
 (1 row)
 
-SELECT date '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' + interval 'infinity';
- ?column? 
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
 ----------
  infinity
 (1 row)
 
-SELECT interval 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT interval '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT interval '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
 
-SELECT interval 'infinity' + interval '10 days';
- ?column? 
-----------
- infinity
-(1 row)
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT interval '-infinity' + interval '10 days';
- ?column?  
------------
- -infinity
-(1 row)
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
 
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
 ERROR:  interval out of range
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
 ERROR:  interval out of range
-SELECT interval 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT interval '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT interval '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT interval 'infinity' - interval '10 days';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT interval '-infinity' - interval '10 days';
- ?column?  
------------
- -infinity
-(1 row)
-
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
 ERROR:  interval out of range
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
 ERROR:  interval out of range
-SELECT timestamp 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamp 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamp '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamp '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamp 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamp 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamp '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamp '-infinity' - interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz 'infinity' + interval 'infinity';
- ?column? 
-----------
- infinity
-(1 row)
-
-SELECT timestamptz 'infinity' + interval '-infinity';
-ERROR:  interval out of range
-SELECT timestamptz '-infinity' + interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamptz '-infinity' + interval '-infinity';
- ?column?  
------------
- -infinity
-(1 row)
-
-SELECT timestamptz 'infinity' - interval 'infinity';
-ERROR:  interval out of range
-SELECT timestamptz 'infinity' - interval '-infinity';
- ?column? 
-----------
- infinity
-(1 row)
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT timestamptz '-infinity' - interval 'infinity';
- ?column?  
------------
- -infinity
-(1 row)
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
 
-SELECT timestamptz '-infinity' - interval '-infinity';
-ERROR:  interval out of range
+-- time +/- infinite interval not supported
 SELECT time '11:27:42' + interval 'infinity';
 ERROR:  cannot add infinite interval to time
 SELECT time '11:27:42' + interval '-infinity';
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index 53542e076b..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2131,7 +2131,7 @@ select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12
 ERROR:  step size cannot be infinite
 -- test arithmetic with infinite timestamps
 select timestamp 'infinity' - timestamp 'infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select timestamp 'infinity' - timestamp '-infinity';
  ?column? 
 ----------
@@ -2145,7 +2145,7 @@ select timestamp '-infinity' - timestamp 'infinity';
 (1 row)
 
 select timestamp '-infinity' - timestamp '-infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
  ?column? 
 ----------
@@ -2172,7 +2172,7 @@ select age(timestamp '-infinity');
 (1 row)
 
 select age(timestamp 'infinity', timestamp 'infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 select age(timestamp 'infinity', timestamp '-infinity');
    age    
 ----------
@@ -2186,4 +2186,4 @@ select age(timestamp '-infinity', timestamp 'infinity');
 (1 row)
 
 select age(timestamp '-infinity', timestamp '-infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index e3f0d918b9..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -3216,7 +3216,7 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 
 -- test arithmetic with infinite timestamps
 SELECT timestamptz 'infinity' - timestamptz 'infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT timestamptz 'infinity' - timestamptz '-infinity';
  ?column? 
 ----------
@@ -3230,7 +3230,7 @@ SELECT timestamptz '-infinity' - timestamptz 'infinity';
 (1 row)
 
 SELECT timestamptz '-infinity' - timestamptz '-infinity';
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
  ?column? 
 ----------
@@ -3257,7 +3257,7 @@ SELECT age(timestamptz '-infinity');
 (1 row)
 
 SELECT age(timestamptz 'infinity', timestamptz 'infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
 SELECT age(timestamptz 'infinity', timestamptz '-infinity');
    age    
 ----------
@@ -3271,4 +3271,4 @@ SELECT age(timestamptz '-infinity', timestamptz 'infinity');
 (1 row)
 
 SELECT age(timestamptz '-infinity', timestamptz '-infinity');
-ERROR:  timestamp out of range
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 63f36e069e..6b8c3c3413 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,9 +2419,70 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2424,7 +2490,8 @@ window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2499,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2510,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,9 +2519,70 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2460,6 +2590,7 @@ window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2601,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2610,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,7 +2621,68 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2496,6 +2690,7 @@ window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2701,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2710,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,7 +2721,68 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2532,6 +2790,7 @@ window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2801,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2810,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,7 +2821,68 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
@@ -4375,36 +4697,34 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
--- window function over interval, infinity and extreme values test the
--- behaviour of accumulation and elimination of these values as the window
--- slides.
+-- moving aggregates over infinite intervals
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
         ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
-               ('2147483647 days 2147483646 months'), -- extreme interval value
-               ('infinity'::timestamptz - now()),
-               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
                ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
                (NULL::interval),
                ('-infinity'::interval)) v(x);
-                      x                       |   curr_next_avg   |  prev1_curr_avg   | curr_next_sum | prev1_curr_sum 
-----------------------------------------------+-------------------+-------------------+---------------+----------------
-                                              | infinity          |                   | infinity      | 
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 178956970 years 6 mons 2147483647 days     | infinity          | infinity          | infinity      | infinity
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 178956970 years 7 mons 2147483648 days ago | infinity          | infinity          | infinity      | infinity
- infinity                                     | infinity          | infinity          | infinity      | infinity
- @ 6 days                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
- @ 7 days                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
-                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
- -infinity                                    | -infinity         | -infinity         | -infinity     | -infinity
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
 (10 rows)
 
 --should fail.
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 414c12be1c..1bffa50fe9 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -73,11 +73,11 @@ SELECT r1.*, r2.*
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
-  ('2147483647 days 2147483646 months'),
-  ('2147483647 days -2147483647 months'),
+  ('2147483647 days 2147483647 months'),
+  ('2147483647 days -2147483648 months'),
   ('1 year'),
-  ('-2147483648 days 2147483646 months'),
-  ('-2147483648 days -2147483647 months');
+  ('-2147483648 days 2147483647 months'),
+  ('-2147483648 days -2147483648 months');
 -- these should fail as out-of-range
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483648 days');
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
@@ -164,8 +164,7 @@ SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
 SELECT justify_hours(interval '2147483647 days 24 hrs');
-SELECT justify_days(interval '2147483646 months 30 days');
-SELECT justify_days(interval '2147483646 months 60 days');
+SELECT justify_days(interval '2147483647 months 30 days');
 
 -- test justify_interval()
 
@@ -173,14 +172,12 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 SELECT justify_interval(interval '2147483647 days 24 hrs');
 SELECT justify_interval(interval '-2147483648 days -24 hrs');
-SELECT justify_interval(interval '2147483646 months 30 days');
-SELECT justify_interval(interval '2147483646 months 60 days');
-SELECT justify_interval(interval '-2147483647 months -30 days');
-SELECT justify_interval(interval '-2147483647 months -60 days');
-SELECT justify_interval(interval '2147483646 months 30 days -24 hrs');
-SELECT justify_interval(interval '-2147483647 months -30 days 24 hrs');
-SELECT justify_interval(interval '2147483646 months -30 days 1440 hrs');
-SELECT justify_interval(interval '-2147483647 months 30 days -1440 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
@@ -608,6 +605,14 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
 -- infinite intervals
 SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
 SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
@@ -617,54 +622,64 @@ INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2
 
 SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
 
-SELECT date '1995-08-06' + interval 'infinity';
-SELECT date '1995-08-06' + interval '-infinity';
-SELECT date '1995-08-06' - interval 'infinity';
-SELECT date '1995-08-06' - interval '-infinity';
-SELECT date 'infinity' + interval 'infinity';
-SELECT date 'infinity' + interval '-infinity';
-SELECT date '-infinity' + interval 'infinity';
-SELECT date '-infinity' + interval '-infinity';
-SELECT date 'infinity' - interval 'infinity';
-SELECT date 'infinity' - interval '-infinity';
-SELECT date '-infinity' - interval 'infinity';
-SELECT date '-infinity' - interval '-infinity';
-SELECT interval 'infinity' + interval 'infinity';
-SELECT interval 'infinity' + interval '-infinity';
-SELECT interval '-infinity' + interval 'infinity';
-SELECT interval '-infinity' + interval '-infinity';
-SELECT interval 'infinity' + interval '10 days';
-SELECT interval '-infinity' + interval '10 days';
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
-SELECT interval 'infinity' - interval 'infinity';
-SELECT interval 'infinity' - interval '-infinity';
-SELECT interval '-infinity' - interval 'infinity';
-SELECT interval '-infinity' - interval '-infinity';
-SELECT interval 'infinity' - interval '10 days';
-SELECT interval '-infinity' - interval '10 days';
 SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
 SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
-SELECT timestamp 'infinity' + interval 'infinity';
-SELECT timestamp 'infinity' + interval '-infinity';
-SELECT timestamp '-infinity' + interval 'infinity';
-SELECT timestamp '-infinity' + interval '-infinity';
-SELECT timestamp 'infinity' - interval 'infinity';
-SELECT timestamp 'infinity' - interval '-infinity';
-SELECT timestamp '-infinity' - interval 'infinity';
-SELECT timestamp '-infinity' - interval '-infinity';
-SELECT timestamptz '1995-08-06 12:30:15' + interval 'infinity';
-SELECT timestamptz '1995-08-06 12:30:15' + interval '-infinity';
-SELECT timestamptz '1995-08-06 12:30:15' - interval 'infinity';
-SELECT timestamptz '1995-08-06 12:30:15' - interval '-infinity';
-SELECT timestamptz 'infinity' + interval 'infinity';
-SELECT timestamptz 'infinity' + interval '-infinity';
-SELECT timestamptz '-infinity' + interval 'infinity';
-SELECT timestamptz '-infinity' + interval '-infinity';
-SELECT timestamptz 'infinity' - interval 'infinity';
-SELECT timestamptz 'infinity' - interval '-infinity';
-SELECT timestamptz '-infinity' - interval 'infinity';
-SELECT timestamptz '-infinity' - interval '-infinity';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
 SELECT time '11:27:42' + interval 'infinity';
 SELECT time '11:27:42' + interval '-infinity';
 SELECT time '11:27:42' - interval 'infinity';
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 6dd9885949..c2a4cb8d64 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,21 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +721,21 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +746,21 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +771,21 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +796,21 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,19 +1668,17 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
--- window function over interval, infinity and extreme values test the
--- behaviour of accumulation and elimination of these values as the window
--- slides.
+-- moving aggregates over infinite intervals
 SELECT  x
         ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
-        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
         ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
-        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev1_curr_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
 FROM (VALUES (NULL::interval),
                ('infinity'::interval),
-               ('2147483647 days 2147483646 months'), -- extreme interval value
-               ('infinity'::timestamptz - now()),
-               ('-2147483648 days -2147483647 months'), -- extreme interval value
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
                ('infinity'::interval),
                ('6 days'::interval),
                ('7 days'::interval),
-- 
2.35.3

From d17168a500f833ccb4139b9ab4b0ea2a40baa76e Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Fri, 6 Oct 2023 11:58:21 +0530
Subject: [PATCH v27 8/8] Add tests for "invalid preceding or following size in
 window function"

Ashutosh Bapat
---
 src/test/regress/expected/window.out | 55 ++++++++++++++++++++++++++++
 src/test/regress/sql/window.sql      | 55 ++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)

diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 6b8c3c3413..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2424,6 +2424,11 @@ window w as (order by f_time desc range between
   0 | 10:00:00 |           1 |          0
 (12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
@@ -2484,6 +2489,12 @@ window w as (order by f_time range between
  11 | 21:00:00 |             |           
 (12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -2524,6 +2535,11 @@ window w as (order by f_timetz desc range between
   0 | 10:00:00+01 |           1 |          0
 (12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -2584,6 +2600,12 @@ window w as (order by f_timetz range between
  11 | 21:00:00+01 |             |           
 (12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -2624,6 +2646,11 @@ window w as (order by f_interval desc range between
   0 | -infinity  |           0 |          0
 (12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -2684,6 +2711,12 @@ window w as (order by f_interval range between
  11 | infinity   |          11 |         11
 (12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -2724,6 +2757,11 @@ window w as (order by f_timestamptz desc range between
   0 | -infinity                    |           0 |          0
 (12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -2784,6 +2822,12 @@ window w as (order by f_timestamptz range between
  11 | infinity                     |          11 |         11
 (12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -2824,6 +2868,11 @@ window w as (order by f_timestamp desc range between
   0 | -infinity                |           0 |          0
 (12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -2884,6 +2933,12 @@ window w as (order by f_timestamp range between
  11 | infinity                 |          11 |         11
 (12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index c2a4cb8d64..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -696,6 +696,11 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
@@ -711,6 +716,12 @@ from datetimes
 window w as (order by f_time range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -721,6 +732,11 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -736,6 +752,12 @@ from datetimes
 window w as (order by f_timetz range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -746,6 +768,11 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -761,6 +788,12 @@ from datetimes
 window w as (order by f_interval range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -771,6 +804,11 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -786,6 +824,12 @@ from datetimes
 window w as (order by f_timestamptz range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -796,6 +840,11 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -811,6 +860,12 @@ from datetimes
 window w as (order by f_timestamp range between
              'infinity'::interval following and 'infinity'::interval following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
-- 
2.35.3

From e8a12155a8822fd76d81eb250d64e0e6a1b9fdd1 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH v28] Support infinite interval values.

Details ...

Joseph Koshakow, Jian He, and Ashutosh Bapat, reviewed by Dean Rasheed.

Discussion: https://postgr.es/m/CAAvxfHea4%2BsPybKK7agDYOMo9N-Z3J6ZXf3BOM79pFsFNcRjwA%40mail.gmail.com
---
 contrib/btree_gin/btree_gin.c             |    5 +-
 doc/src/sgml/datatype.sgml                |    4 +-
 doc/src/sgml/func.sgml                    |    8 +-
 src/backend/utils/adt/date.c              |   57 +-
 src/backend/utils/adt/datetime.c          |   26 +
 src/backend/utils/adt/formatting.c        |    2 +-
 src/backend/utils/adt/selfuncs.c          |    4 +
 src/backend/utils/adt/timestamp.c         | 1146 ++++++++++++++++-----
 src/include/catalog/pg_aggregate.dat      |   24 +-
 src/include/catalog/pg_proc.dat           |   28 +-
 src/include/datatype/timestamp.h          |   27 +-
 src/test/regress/expected/horology.out    |   73 +-
 src/test/regress/expected/interval.out    |  455 +++++++-
 src/test/regress/expected/timestamp.out   |   62 ++
 src/test/regress/expected/timestamptz.out |   62 ++
 src/test/regress/expected/window.out      |  469 ++++++++-
 src/test/regress/sql/horology.sql         |    5 +-
 src/test/regress/sql/interval.sql         |  182 +++-
 src/test/regress/sql/timestamp.sql        |   19 +
 src/test/regress/sql/timestamptz.sql      |   18 +
 src/test/regress/sql/window.sql           |  167 ++-
 src/tools/pgindent/typedefs.list          |    1 +
 22 files changed, 2510 insertions(+), 334 deletions(-)

diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
index b09bb8df96..5e27906f80 100644
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,8 @@ leftmostvalue_interval(void)
 {
 	Interval   *v = palloc(sizeof(Interval));
 
-	v->time = PG_INT64_MIN;
-	v->day = PG_INT32_MIN;
-	v->month = PG_INT32_MIN;
+	INTERVAL_NOBEGIN(v);
+
 	return IntervalPGetDatum(v);
 }
 
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5d23765705..123d8207f8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,12 +2321,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index c76ec52c55..578079dd89 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,11 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 56c7746c11..cafe3abe21 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2014,6 +2015,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2058,6 +2064,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2087,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2099,7 +2115,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2109,13 +2126,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2590,6 +2608,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2635,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -2639,7 +2667,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2649,13 +2678,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
@@ -3105,6 +3135,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3574,6 +3577,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -3597,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * Infinity cannot be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but using signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4802,6 +4802,10 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				 * Convert the month part of Interval to days using assumed
 				 * average month length of 365.25/12.0 days.  Not too
 				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
 				 */
 				return interval->time + interval->day * (double) USECS_PER_DAY +
 					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..23d43094e8 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -72,6 +72,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -80,6 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +962,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +992,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1384,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1577,9 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1604,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2038,12 +2093,21 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2088,7 +2152,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2442,6 +2508,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2714,46 +2789,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2783,6 +2883,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2835,6 +2938,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2858,6 +2966,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2875,6 +2986,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2896,6 +3012,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2914,6 +3033,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2934,7 +3058,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3160,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3187,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3300,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3351,27 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(const Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3379,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3423,33 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinite intervals
+	 * with different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3463,35 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3516,47 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		result_sign = interval_sign(span) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3617,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3653,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3697,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3466,11 +3725,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3493,11 +3762,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3524,11 +3803,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3547,161 +3836,387 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
  */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
 
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Functions to add or subtract finite intervals.
+ *
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
+ */
+static void
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
+	state->N++;
+}
+
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle to be discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_accum(PG_FUNCTION_ARGS)
+interval_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
+
+/*
+ * Combine function for sum() and avg() interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	if (state1 == NULL)
+	{
+		/* manually copy all fields from state2 to state1 */
+		state1 = makeIntervalAggState(fcinfo);
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* Accumulate finite interval values, if any. */
+	if (state2->N > 0)
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_serialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
 
-	Interval   *newsum;
-	ArrayType  *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+	pq_begintypsend(&buf);
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* N */
+	pq_sendint64(&buf, state->N);
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+	/* sumX */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	result = pq_endtypsend(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_BYTEA_P(result);
 }
 
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_deserialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	sstate = PG_GETARG_BYTEA_PP(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
+
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	/* sumX */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
 }
 
+/*
+ * Inverse transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
+	{
+		Interval   *result;
+
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *result;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (state->pInfcount > 0)
+		INTERVAL_NOEND(result);
+	else if (state->nInfcount > 0)
+		INTERVAL_NOBEGIN(result);
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
+
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
@@ -3726,8 +4241,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4388,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4541,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4729,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4972,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5322,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5596,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5836,58 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5912,33 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval));
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +6181,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6418,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5783,7 +6461,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5806,13 +6483,18 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5864,7 +6546,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5888,13 +6569,18 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,13 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index bc41e92677..455ed16c79 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,29 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,6 +168,31 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..00cd3e84f1 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +268,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -304,6 +347,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
@@ -386,12 +440,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +876,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +888,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1674,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1777,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1865,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1876,292 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
+(1 row)
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
+----------
+ infinity
+(1 row)
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
@@ -1832,3 +2180,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  interval out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  interval out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,17 +2419,90 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2510,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2521,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,16 +2530,89 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2623,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2632,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,14 +2643,87 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2734,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2743,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,14 +2754,87 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2845,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2854,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,8 +2865,80 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -4375,6 +4752,52 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..1bffa50fe9 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -95,6 +99,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
@@ -140,7 +147,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -528,13 +535,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +605,157 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
@@ -605,3 +763,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,32 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +732,32 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +768,32 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +804,32 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +840,32 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,6 +1723,39 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 87c1aee379..236683e5ab 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3

From e8a12155a8822fd76d81eb250d64e0e6a1b9fdd1 Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <koshy44@gmail.com>
Date: Sat, 18 Mar 2023 13:59:34 -0400
Subject: [PATCH v28] Support infinite interval values.

Details ...

Joseph Koshakow, Jian He, and Ashutosh Bapat, reviewed by Dean Rasheed.

Discussion: https://postgr.es/m/CAAvxfHea4%2BsPybKK7agDYOMo9N-Z3J6ZXf3BOM79pFsFNcRjwA%40mail.gmail.com
---
 contrib/btree_gin/btree_gin.c             |    5 +-
 doc/src/sgml/datatype.sgml                |    4 +-
 doc/src/sgml/func.sgml                    |    8 +-
 src/backend/utils/adt/date.c              |   57 +-
 src/backend/utils/adt/datetime.c          |   26 +
 src/backend/utils/adt/formatting.c        |    2 +-
 src/backend/utils/adt/selfuncs.c          |    4 +
 src/backend/utils/adt/timestamp.c         | 1146 ++++++++++++++++-----
 src/include/catalog/pg_aggregate.dat      |   24 +-
 src/include/catalog/pg_proc.dat           |   28 +-
 src/include/datatype/timestamp.h          |   27 +-
 src/test/regress/expected/horology.out    |   73 +-
 src/test/regress/expected/interval.out    |  455 +++++++-
 src/test/regress/expected/timestamp.out   |   62 ++
 src/test/regress/expected/timestamptz.out |   62 ++
 src/test/regress/expected/window.out      |  469 ++++++++-
 src/test/regress/sql/horology.sql         |    5 +-
 src/test/regress/sql/interval.sql         |  182 +++-
 src/test/regress/sql/timestamp.sql        |   19 +
 src/test/regress/sql/timestamptz.sql      |   18 +
 src/test/regress/sql/window.sql           |  167 ++-
 src/tools/pgindent/typedefs.list          |    1 +
 22 files changed, 2510 insertions(+), 334 deletions(-)

diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
index b09bb8df96..5e27906f80 100644
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,8 @@ leftmostvalue_interval(void)
 {
 	Interval   *v = palloc(sizeof(Interval));
 
-	v->time = PG_INT64_MIN;
-	v->day = PG_INT32_MIN;
-	v->month = PG_INT32_MIN;
+	INTERVAL_NOBEGIN(v);
+
 	return IntervalPGetDatum(v);
 }
 
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5d23765705..123d8207f8 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2321,12 +2321,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index c76ec52c55..578079dd89 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9537,7 +9537,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10434,7 +10434,11 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 56c7746c11..cafe3abe21 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2014,6 +2015,11 @@ interval_time(PG_FUNCTION_ARGS)
 	TimeADT		result;
 	int64		days;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("time out of range")));
+
 	result = span->time;
 	if (result >= USECS_PER_DAY)
 	{
@@ -2058,6 +2064,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2076,6 +2087,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2099,7 +2115,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2109,13 +2126,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2590,6 +2608,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2612,6 +2635,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -2639,7 +2667,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2649,13 +2678,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
@@ -3105,6 +3135,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3574,6 +3577,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -3597,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * Infinity cannot be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but using signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4802,6 +4802,10 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				 * Convert the month part of Interval to days using assumed
 				 * average month length of 365.25/12.0 days.  Not too
 				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
 				 */
 				return interval->time + interval->day * (double) USECS_PER_DAY +
 					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..23d43094e8 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -72,6 +72,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -80,6 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +962,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +992,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1384,13 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/*
+	 * Infinite interval after being subjected to typmod conversion remains
+	 * infinite.
+	 */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1577,9 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1604,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2038,12 +2093,21 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2088,7 +2152,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2442,6 +2508,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2714,46 +2789,71 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
-
-	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
 
-	result->month = 0;
-	result->day = 0;
+		result->month = 0;
+		result->day = 0;
 
-	/*----------
-	 *	This is wrong, but removing it breaks a lot of regression tests.
-	 *	For example:
-	 *
-	 *	test=> SET timezone = 'EST5EDT';
-	 *	test=> SELECT
-	 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
-	 *	?column?
-	 *	----------------
-	 *	 1 day 01:00:00
-	 *	 (1 row)
-	 *
-	 *	so adding that to the first timestamp gets:
-	 *
-	 *	 test=> SELECT
-	 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
-	 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
-	 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
-	 *		timezone
-	 *	--------------------
-	 *	2005-10-30 14:22:00
-	 *	(1 row)
-	 *----------
-	 */
-	result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
-												   IntervalPGetDatum(result)));
+		/*----------
+		 *	This is wrong, but removing it breaks a lot of regression tests.
+		 *	For example:
+		 *
+		 *	test=> SET timezone = 'EST5EDT';
+		 *	test=> SELECT
+		 *	test-> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	test(>	'2005-10-29 13:22:00-04'::timestamptz);
+		 *	?column?
+		 *	----------------
+		 *	 1 day 01:00:00
+		 *	 (1 row)
+		 *
+		 *	so adding that to the first timestamp gets:
+		 *
+		 *	 test=> SELECT
+		 *	 test-> ('2005-10-29 13:22:00-04'::timestamptz +
+		 *	 test(> ('2005-10-30 13:22:00-05'::timestamptz -
+		 *	 test(>  '2005-10-29 13:22:00-04'::timestamptz)) at time zone 'EST';
+		 *		timezone
+		 *	--------------------
+		 *	2005-10-30 14:22:00
+		 *	(1 row)
+		 *----------
+		 */
+		result = DatumGetIntervalP(DirectFunctionCall1(interval_justify_hours,
+													   IntervalPGetDatum(result)));
+	}
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -2783,6 +2883,9 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2835,6 +2938,11 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2858,6 +2966,9 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2875,6 +2986,11 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 		result->day++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2896,6 +3012,9 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2914,6 +3033,11 @@ interval_justify_days(PG_FUNCTION_ARGS)
 		result->month++;
 	}
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -2934,7 +3058,30 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3160,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3187,30 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Adding two infinities with the same sign results in an infinite
+	 * timestamp with the same sign. Adding two infinities with different
+	 * signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3300,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3351,27 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* Negates the given interval */
+static void
+interval_um_internal(const Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		result->time = -interval->time;
+		result->day = -interval->day;
+		result->month = -interval->month;
+
+		if (INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3379,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3423,33 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Adding two infinite intervals with the same signs results in an
+	 * infinite interval with the same sign. Adding two infinite intervals
+	 * with different signs results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3463,35 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Subtracting two infinite intervals with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite intervals with the same sign results in an error.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3516,47 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Multiplying an infinite value by another non-zero value always results
+	 * in an infinite value but, may change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+	else if (isinf(factor))
+	{
+		int			factor_sign,
+					result_sign;
+
+		factor_sign = factor >= 0.0 ? 1 : -1;
+		result_sign = interval_sign(span) * factor_sign;
+
+		if (result_sign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (result_sign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3617,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3653,29 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	/*
+	 * Dividing infinite interval by finite number keeps it infinite but may
+	 * change the sign.
+	 */
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3697,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3466,11 +3725,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3493,11 +3762,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3524,11 +3803,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3547,161 +3836,387 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
  */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
 
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Functions to add or subtract finite intervals.
+ *
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
+ */
+static void
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
+	state->N++;
+}
+
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle to be discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_accum(PG_FUNCTION_ARGS)
+interval_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
+
+/*
+ * Combine function for sum() and avg() interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	if (state1 == NULL)
+	{
+		/* manually copy all fields from state2 to state1 */
+		state1 = makeIntervalAggState(fcinfo);
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* Accumulate finite interval values, if any. */
+	if (state2->N > 0)
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_serialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
 
-	Interval   *newsum;
-	ArrayType  *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+	pq_begintypsend(&buf);
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* N */
+	pq_sendint64(&buf, state->N);
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+	/* sumX */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	result = pq_endtypsend(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_BYTEA_P(result);
 }
 
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_deserialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
+
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	sstate = PG_GETARG_BYTEA_PP(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
+
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	/* N */
+	result->N = pq_getmsgint64(&buf);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	/* sumX */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
 }
 
+/*
+ * Inverse transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
+	{
+		Interval   *result;
+
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *result;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (state->pInfcount > 0)
+		INTERVAL_NOEND(result);
+	else if (state->nInfcount > 0)
+		INTERVAL_NOBEGIN(result);
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
+
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
@@ -3726,8 +4241,35 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4388,35 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Subtracting two infinite timestamps with different signs results in an
+	 * infinite interval with the same sign as the left operand. Subtracting
+	 * two infinite timestamps with the same sign results in an error.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4541,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4729,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4972,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5322,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5596,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5836,58 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5912,33 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval));
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +6181,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6418,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5783,7 +6461,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5806,13 +6483,18 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5864,7 +6546,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5888,13 +6569,18 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,13 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index bc41e92677..455ed16c79 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,29 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,6 +168,31 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..eaf44b960f 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1159,6 +1159,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1266,6 +1267,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1541,9 +1543,26 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1704,14 +1723,46 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1872,7 +1923,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..00cd3e84f1 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,7 +268,18 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
 
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
@@ -304,6 +347,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
@@ -386,12 +440,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +876,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +888,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1674,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1777,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1865,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1876,292 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
+(1 row)
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
+----------
+ infinity
+(1 row)
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  time out of range
+SELECT '-infinity'::interval::time;
+ERROR:  time out of range
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
@@ -1832,3 +2180,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  interval out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  interval out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,17 +2419,90 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2510,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2521,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,16 +2530,89 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2623,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2632,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,14 +2643,87 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2734,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2743,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,14 +2754,87 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2845,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2854,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,8 +2865,80 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -4375,6 +4752,52 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..0b4071f316 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -211,10 +211,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -287,11 +289,12 @@ SELECT f1 AS "timestamp"
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY plus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
+  WHERE isfinite(t.f1) OR isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..1bffa50fe9 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -95,6 +99,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
@@ -140,7 +147,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -528,13 +535,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +605,157 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
@@ -605,3 +763,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,32 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +732,32 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +768,32 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +804,32 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +840,32 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,6 +1723,39 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 87c1aee379..236683e5ab 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3

From ed8279dec49169922c36a1d1696035919611185c Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Mon, 30 Oct 2023 12:37:48 +0530
Subject: [PATCH 2/2] BRIN test for infinite interval values

---
 src/test/regress/expected/brin_multi.out | 28 ++++++++++++++++++++++++
 src/test/regress/sql/brin_multi.sql      | 19 ++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 80801cd4ee..8f4c95b9e6 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -941,6 +941,34 @@ SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
          Index Cond: (a = '@ 30 years'::interval)
 (4 rows)
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+SET enable_seqscan = off;
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years ago'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years ago'::interval)
+(4 rows)
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years'::interval)
+(4 rows)
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index b666dbad67..116106d30f 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -682,6 +682,25 @@ SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
 EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
 SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+
+SET enable_seqscan = off;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
-- 
2.25.1

From aadc2e7306044204a25805e7361539dec2f6a3da Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Sun, 5 Nov 2023 14:45:13 +0000
Subject: [PATCH v29 1/2] Avoid integer overflow hazard in interval_time().

When casting an interval to a time, the original code suffered from
64-bit integer overflow for inputs with a sufficiently large negative
"time" field, leading to bogus results.

Fix by rewriting the algorithm in a simpler form, that more obviously
cannot overflow. While at it, improve the test coverage to test
negative interval inputs.
---
 src/backend/utils/adt/date.c           | 15 +++------------
 src/test/regress/expected/horology.out | 12 ++++++++++++
 src/test/regress/sql/horology.sql      |  2 ++
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 56c7746c11..544e1d32bf 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2012,19 +2012,10 @@ interval_time(PG_FUNCTION_ARGS)
 {
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
-	int64		days;
 
-	result = span->time;
-	if (result >= USECS_PER_DAY)
-	{
-		days = result / USECS_PER_DAY;
-		result -= days * USECS_PER_DAY;
-	}
-	else if (result < 0)
-	{
-		days = (-result + USECS_PER_DAY - 1) / USECS_PER_DAY;
-		result += days * USECS_PER_DAY;
-	}
+	result = span->time % USECS_PER_DAY;
+	if (result < 0)
+		result += USECS_PER_DAY;
 
 	PG_RETURN_TIMEADT(result);
 }
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..8f52661096 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -981,6 +981,18 @@ SELECT CAST(interval '02:03' AS time) AS "02:03:00";
  02:03:00
 (1 row)
 
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+ 21:57:00 
+----------
+ 21:57:00
+(1 row)
+
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
+ 00:00:00 
+----------
+ 00:00:00
+(1 row)
+
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
  03:31:00 
 ----------
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..39a35a6b7c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -182,6 +182,8 @@ SELECT d1 - interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
 
 SELECT CAST(time '01:02' AS interval) AS "+01:02";
 SELECT CAST(interval '02:03' AS time) AS "02:03:00";
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
 SELECT time '01:30' - interval '02:01' AS "23:29:00";
 SELECT time '02:30' + interval '36:01' AS "14:31:00";
-- 
2.35.3

From 9e0c8e67955b5d8890c6fb099b6941dcd12f6c8f Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Mon, 6 Nov 2023 13:52:27 +0000
Subject: [PATCH v29 2/2] Support +/- infinity in the interval data type.

This adds support for infinity to the interval data type, using the
same input/output representation as the other date/time data types
that support infinity. This allows various arithmetic operations on
infinite dates, timestamps and intervals.

The new values are represented by setting all fields of the interval
to INT32/64_MIN for -infinity, and INT32/64_MAX for +infinity. This
ensures that they compare as less/greater than all other interval
values, without the need for any special-case comparison code.

Note that, since those 2 values were formerly accepted as legal finite
intervals, pg_upgrade and dump/restore from an old database will turn
them from finite to infinite intervals. That seems OK, since those
exact values should be extremely rare in practice, and they are
outside the documented range supported by the interval type, which
gives us a certain amount of leeway.

Joseph Koshakow, Jian He, and Ashutosh Bapat, reviewed by Dean Rasheed.

Discussion: https://postgr.es/m/CAAvxfHea4%2BsPybKK7agDYOMo9N-Z3J6ZXf3BOM79pFsFNcRjwA%40mail.gmail.com
---
 contrib/btree_gin/btree_gin.c             |    5 +-
 doc/src/sgml/datatype.sgml                |    4 +-
 doc/src/sgml/func.sgml                    |    8 +-
 src/backend/utils/adt/date.c              |   57 +-
 src/backend/utils/adt/datetime.c          |   26 +
 src/backend/utils/adt/formatting.c        |    2 +-
 src/backend/utils/adt/selfuncs.c          |    4 +
 src/backend/utils/adt/timestamp.c         | 1080 +++++++++++++++++----
 src/include/catalog/pg_aggregate.dat      |   24 +-
 src/include/catalog/pg_proc.dat           |   28 +-
 src/include/datatype/timestamp.h          |   27 +-
 src/test/regress/expected/brin_multi.out  |   28 +
 src/test/regress/expected/horology.out    |   71 +-
 src/test/regress/expected/interval.out    |  499 +++++++++-
 src/test/regress/expected/timestamp.out   |   62 ++
 src/test/regress/expected/timestamptz.out |   62 ++
 src/test/regress/expected/window.out      |  469 ++++++++-
 src/test/regress/sql/brin_multi.sql       |   19 +
 src/test/regress/sql/horology.sql         |    3 +-
 src/test/regress/sql/interval.sql         |  193 +++-
 src/test/regress/sql/timestamp.sql        |   19 +
 src/test/regress/sql/timestamptz.sql      |   18 +
 src/test/regress/sql/window.sql           |  167 +++-
 src/tools/pgindent/typedefs.list          |    1 +
 24 files changed, 2577 insertions(+), 299 deletions(-)

diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
index b09bb8df96..5e27906f80 100644
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,8 @@ leftmostvalue_interval(void)
 {
 	Interval   *v = palloc(sizeof(Interval));
 
-	v->time = PG_INT64_MIN;
-	v->day = PG_INT32_MIN;
-	v->month = PG_INT32_MIN;
+	INTERVAL_NOBEGIN(v);
+
 	return IntervalPGetDatum(v);
 }
 
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5a6cfbd94d..4aba6d19ee 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2328,12 +2328,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index a6fcac0824..1156eea6ee 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9553,7 +9553,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10450,7 +10450,11 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 544e1d32bf..13745a0adc 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2013,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot convert infinite interval to time")));
+
 	result = span->time % USECS_PER_DAY;
 	if (result < 0)
 		result += USECS_PER_DAY;
@@ -2049,6 +2055,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2067,6 +2078,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2090,7 +2106,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2100,13 +2117,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2581,6 +2599,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2603,6 +2626,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -2630,7 +2658,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2640,13 +2669,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
@@ -3096,6 +3126,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3574,6 +3577,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -3597,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * Infinity cannot be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but using signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4802,6 +4802,10 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				 * Convert the month part of Interval to days using assumed
 				 * average month length of 365.25/12.0 days.  Not too
 				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
 				 */
 				return interval->time + interval->day * (double) USECS_PER_DAY +
 					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..0aee842752 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -72,6 +72,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -80,6 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +962,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +992,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1384,10 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/* Typmod has no effect on infinite intervals */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1574,10 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	/* make sure that the result is finite */
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1602,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2015,6 +2068,9 @@ interval2itm(Interval span, struct pg_itm *itm)
 /* itm2interval()
  * Convert a pg_itm structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * This is for use in computations expected to produce finite results.  Any
+ * inputs that lead to infinite results are treated as overflows.
  */
 int
 itm2interval(struct pg_itm *itm, Interval *span)
@@ -2038,12 +2094,21 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2088,7 +2153,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2442,6 +2509,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2714,10 +2790,39 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
 	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt1))
+		{
+			if (TIMESTAMP_IS_NOBEGIN(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOBEGIN(result);
+		}
+		else if (TIMESTAMP_IS_NOEND(dt1))
+		{
+			if (TIMESTAMP_IS_NOEND(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOEND(result);
+		}
+		else if (TIMESTAMP_IS_NOBEGIN(dt2))
+			INTERVAL_NOEND(result);
+		else					/* TIMESTAMP_IS_NOEND(dt2) */
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
 
 	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
 		ereport(ERROR,
@@ -2783,6 +2888,10 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2858,6 +2967,10 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2896,6 +3009,10 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2934,7 +3051,31 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamp type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3181,31 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamptz type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3295,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3346,29 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* interval_um_internal()
+ * Negate an interval.
+ */
+static void
+interval_um_internal(const Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		/* Negate each field, guarding against overflow */
+		if (pg_sub_s64_overflow(0, interval->time, &result->time) ||
+			pg_sub_s32_overflow(0, interval->day, &result->day) ||
+			pg_sub_s32_overflow(0, interval->month, &result->month) ||
+			INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3376,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3420,34 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3461,36 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3515,46 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "0 * infinity" and "infinity * 0" as errors, since the
+	 * interval type has nothing equivalent to NaN.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+	if (isinf(factor))
+	{
+		int			isign = interval_sign(span);
+
+		if (isign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor * isign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3615,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3651,33 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "infinity / infinity" as an error, since the interval type has
+	 * nothing equivalent to NaN.  Otherwise, dividing by infinity is handled
+	 * by the regular division code, causing all fields to be set to zero.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3699,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3466,11 +3727,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3493,11 +3764,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3524,11 +3805,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3547,161 +3838,387 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Functions to add or subtract finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
  */
+static void
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
+	state->N++;
+}
+
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle the to-be-discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_accum(PG_FUNCTION_ARGS)
+interval_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/*
+ * Combine function for sum() and avg() interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	if (state1 == NULL)
+	{
+		/* manually copy all fields from state2 to state1 */
+		state1 = makeIntervalAggState(fcinfo);
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	/* Accumulate finite interval values, if any. */
+	if (state2->N > 0)
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
+
+	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_serialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
 
-	Interval   *newsum;
-	ArrayType  *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+	pq_begintypsend(&buf);
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* N */
+	pq_sendint64(&buf, state->N);
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+	/* sumX */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	result = pq_endtypsend(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_BYTEA_P(result);
 }
 
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_deserialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	sstate = PG_GETARG_BYTEA_PP(0);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* N */
+	result->N = pq_getmsgint64(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* sumX */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
 }
 
+/*
+ * Inverse transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
+
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
+	{
+		Interval   *result;
+
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *result;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (state->pInfcount > 0)
+		INTERVAL_NOEND(result);
+	else if (state->nInfcount > 0)
+		INTERVAL_NOBEGIN(result);
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
+
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
@@ -3726,8 +4243,36 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4391,36 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4545,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4733,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4976,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5326,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5600,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5840,58 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5916,33 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval));
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +6185,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6422,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5783,7 +6465,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5806,13 +6487,18 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5864,7 +6550,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5888,13 +6573,18 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,13 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 091f7e343c..868add0224 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,29 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum_inv' },
+{ oid => '3813', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '3814', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8069', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,6 +168,31 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 80801cd4ee..8f4c95b9e6 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -941,6 +941,34 @@ SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
          Index Cond: (a = '@ 30 years'::interval)
 (4 rows)
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+SET enable_seqscan = off;
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years ago'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years ago'::interval)
+(4 rows)
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years'::interval)
+(4 rows)
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index 8f52661096..cfb4b205e4 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1171,6 +1171,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1278,6 +1279,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1556,6 +1558,22 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1716,14 +1734,45 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1884,7 +1933,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..a481781475 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,8 +268,63 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
+
+-- test unary minus
+SELECT f1, -f1 FROM INTERVAL_TBL;
+       f1        |     ?column?      
+-----------------+-------------------
+ 00:01:00        | -00:01:00
+ 05:00:00        | -05:00:00
+ 10 days         | -10 days
+ 34 years        | -34 years
+ 3 mons          | -3 mons
+ -00:00:14       | 00:00:14
+ 1 day 02:03:04  | -1 days -02:03:04
+ 6 years         | -6 years
+ 5 mons          | -5 mons
+ 5 mons 12:00:00 | -5 mons -12:00:00
+ infinity        | -infinity
+ -infinity       | infinity
+(12 rows)
+
+SELECT -('-2147483648 months'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 months'::interval); -- ok
+        ?column?        
+------------------------
+ 178956970 years 7 mons
+(1 row)
+
+SELECT -('-2147483648 days'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 days'::interval); -- ok
+    ?column?     
+-----------------
+ 2147483647 days
+(1 row)
+
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-9223372036854775807 us'::interval); -- ok
+        ?column?         
+-------------------------
+ 2562047788:00:54.775807
+(1 row)
 
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+ERROR:  interval out of range
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -304,6 +391,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
@@ -386,12 +484,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +920,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +932,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1718,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1821,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1909,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1920,292 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
+(1 row)
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
+----------
+ infinity
+(1 row)
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT '-infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
@@ -1832,3 +2224,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  interval out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  interval out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,17 +2419,90 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2510,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2521,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,16 +2530,89 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2623,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2632,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,14 +2643,87 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2734,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2743,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,14 +2754,87 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2845,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2854,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,8 +2865,80 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -4375,6 +4752,52 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index b666dbad67..116106d30f 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -682,6 +682,25 @@ SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
 EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
 SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+
+SET enable_seqscan = off;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 39a35a6b7c..252bce4b1c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -213,10 +213,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -293,7 +295,6 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..caad291890 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -66,6 +70,17 @@ SELECT r1.*, r2.*
    WHERE r1.f1 > r2.f1
    ORDER BY r1.f1, r2.f1;
 
+-- test unary minus
+
+SELECT f1, -f1 FROM INTERVAL_TBL;
+SELECT -('-2147483648 months'::interval); -- should fail
+SELECT -('-2147483647 months'::interval); -- ok
+SELECT -('-2147483648 days'::interval); -- should fail
+SELECT -('-2147483647 days'::interval); -- ok
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+SELECT -('-9223372036854775807 us'::interval); -- ok
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -95,6 +110,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
@@ -140,7 +158,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -528,13 +546,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +616,157 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
@@ -605,3 +774,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,32 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +732,32 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +768,32 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +804,32 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +840,32 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,6 +1723,39 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 87c1aee379..236683e5ab 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3

From dbc3e01bbe79786c345e6c454bcfe583370098f2 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Sun, 5 Nov 2023 14:45:13 +0000
Subject: [PATCH v30 1/2] Avoid integer overflow hazard in interval_time().

When casting an interval to a time, the original code suffered from
64-bit integer overflow for inputs with a sufficiently large negative
"time" field, leading to bogus results.

Fix by rewriting the algorithm in a simpler form, that more obviously
cannot overflow. While at it, improve the test coverage to test
negative interval inputs.
---
 src/backend/utils/adt/date.c           | 15 +++------------
 src/test/regress/expected/horology.out | 12 ++++++++++++
 src/test/regress/sql/horology.sql      |  2 ++
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 56c7746c11..544e1d32bf 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2012,19 +2012,10 @@ interval_time(PG_FUNCTION_ARGS)
 {
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
-	int64		days;
 
-	result = span->time;
-	if (result >= USECS_PER_DAY)
-	{
-		days = result / USECS_PER_DAY;
-		result -= days * USECS_PER_DAY;
-	}
-	else if (result < 0)
-	{
-		days = (-result + USECS_PER_DAY - 1) / USECS_PER_DAY;
-		result += days * USECS_PER_DAY;
-	}
+	result = span->time % USECS_PER_DAY;
+	if (result < 0)
+		result += USECS_PER_DAY;
 
 	PG_RETURN_TIMEADT(result);
 }
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..8f52661096 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -981,6 +981,18 @@ SELECT CAST(interval '02:03' AS time) AS "02:03:00";
  02:03:00
 (1 row)
 
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+ 21:57:00 
+----------
+ 21:57:00
+(1 row)
+
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
+ 00:00:00 
+----------
+ 00:00:00
+(1 row)
+
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
  03:31:00 
 ----------
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..39a35a6b7c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -182,6 +182,8 @@ SELECT d1 - interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
 
 SELECT CAST(time '01:02' AS interval) AS "+01:02";
 SELECT CAST(interval '02:03' AS time) AS "02:03:00";
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
 SELECT time '01:30' - interval '02:01' AS "23:29:00";
 SELECT time '02:30' + interval '36:01' AS "14:31:00";
-- 
2.35.3

From 1a8df3660270f6d462ae5eee1ad3264542d0ea61 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Mon, 6 Nov 2023 13:52:27 +0000
Subject: [PATCH v30 2/2] Support +/- infinity in the interval data type.

This adds support for infinity to the interval data type, using the
same input/output representation as the other date/time data types
that support infinity. This allows various arithmetic operations on
infinite dates, timestamps and intervals.

The new values are represented by setting all fields of the interval
to INT32/64_MIN for -infinity, and INT32/64_MAX for +infinity. This
ensures that they compare as less/greater than all other interval
values, without the need for any special-case comparison code.

Note that, since those 2 values were formerly accepted as legal finite
intervals, pg_upgrade and dump/restore from an old database will turn
them from finite to infinite intervals. That seems OK, since those
exact values should be extremely rare in practice, and they are
outside the documented range supported by the interval type, which
gives us a certain amount of leeway.

Joseph Koshakow, Jian He, and Ashutosh Bapat, reviewed by Dean Rasheed.

Discussion: https://postgr.es/m/CAAvxfHea4%2BsPybKK7agDYOMo9N-Z3J6ZXf3BOM79pFsFNcRjwA%40mail.gmail.com
---
 contrib/btree_gin/btree_gin.c             |    5 +-
 doc/src/sgml/datatype.sgml                |    4 +-
 doc/src/sgml/func.sgml                    |    8 +-
 src/backend/utils/adt/date.c              |   57 +-
 src/backend/utils/adt/datetime.c          |   26 +
 src/backend/utils/adt/formatting.c        |    2 +-
 src/backend/utils/adt/selfuncs.c          |    4 +
 src/backend/utils/adt/timestamp.c         | 1080 +++++++++++++++++----
 src/include/catalog/pg_aggregate.dat      |   24 +-
 src/include/catalog/pg_proc.dat           |   28 +-
 src/include/datatype/timestamp.h          |   27 +-
 src/test/regress/expected/brin_multi.out  |   28 +
 src/test/regress/expected/horology.out    |   71 +-
 src/test/regress/expected/interval.out    |  499 +++++++++-
 src/test/regress/expected/timestamp.out   |   62 ++
 src/test/regress/expected/timestamptz.out |   62 ++
 src/test/regress/expected/window.out      |  469 ++++++++-
 src/test/regress/sql/brin_multi.sql       |   19 +
 src/test/regress/sql/horology.sql         |    3 +-
 src/test/regress/sql/interval.sql         |  193 +++-
 src/test/regress/sql/timestamp.sql        |   19 +
 src/test/regress/sql/timestamptz.sql      |   18 +
 src/test/regress/sql/window.sql           |  167 +++-
 src/tools/pgindent/typedefs.list          |    1 +
 24 files changed, 2577 insertions(+), 299 deletions(-)

diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
index b09bb8df96..5e27906f80 100644
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,8 @@ leftmostvalue_interval(void)
 {
 	Interval   *v = palloc(sizeof(Interval));
 
-	v->time = PG_INT64_MIN;
-	v->day = PG_INT32_MIN;
-	v->month = PG_INT32_MIN;
+	INTERVAL_NOBEGIN(v);
+
 	return IntervalPGetDatum(v);
 }
 
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5a6cfbd94d..4aba6d19ee 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2328,12 +2328,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d963f0a0a0..146d71dd9f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9553,7 +9553,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10450,7 +10450,11 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 544e1d32bf..13745a0adc 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2013,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot convert infinite interval to time")));
+
 	result = span->time % USECS_PER_DAY;
 	if (result < 0)
 		result += USECS_PER_DAY;
@@ -2049,6 +2055,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2067,6 +2078,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2090,7 +2106,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2100,13 +2117,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2581,6 +2599,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2603,6 +2626,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -2630,7 +2658,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2640,13 +2669,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
@@ -3096,6 +3126,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3574,6 +3577,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -3597,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * Infinity cannot be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but using signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4802,6 +4802,10 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				 * Convert the month part of Interval to days using assumed
 				 * average month length of 365.25/12.0 days.  Not too
 				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
 				 */
 				return interval->time + interval->day * (double) USECS_PER_DAY +
 					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..0aee842752 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -72,6 +72,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -80,6 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +962,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +992,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1384,10 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/* Typmod has no effect on infinite intervals */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1574,10 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	/* make sure that the result is finite */
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1602,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2015,6 +2068,9 @@ interval2itm(Interval span, struct pg_itm *itm)
 /* itm2interval()
  * Convert a pg_itm structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * This is for use in computations expected to produce finite results.  Any
+ * inputs that lead to infinite results are treated as overflows.
  */
 int
 itm2interval(struct pg_itm *itm, Interval *span)
@@ -2038,12 +2094,21 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2088,7 +2153,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2442,6 +2509,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2714,10 +2790,39 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
 	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt1))
+		{
+			if (TIMESTAMP_IS_NOBEGIN(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOBEGIN(result);
+		}
+		else if (TIMESTAMP_IS_NOEND(dt1))
+		{
+			if (TIMESTAMP_IS_NOEND(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOEND(result);
+		}
+		else if (TIMESTAMP_IS_NOBEGIN(dt2))
+			INTERVAL_NOEND(result);
+		else					/* TIMESTAMP_IS_NOEND(dt2) */
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
 
 	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
 		ereport(ERROR,
@@ -2783,6 +2888,10 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2858,6 +2967,10 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2896,6 +3009,10 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2934,7 +3051,31 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamp type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3181,31 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamptz type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3295,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3346,29 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* interval_um_internal()
+ * Negate an interval.
+ */
+static void
+interval_um_internal(const Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		/* Negate each field, guarding against overflow */
+		if (pg_sub_s64_overflow(0, interval->time, &result->time) ||
+			pg_sub_s32_overflow(0, interval->day, &result->day) ||
+			pg_sub_s32_overflow(0, interval->month, &result->month) ||
+			INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3376,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3420,34 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3461,36 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3515,46 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "0 * infinity" and "infinity * 0" as errors, since the
+	 * interval type has nothing equivalent to NaN.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+	if (isinf(factor))
+	{
+		int			isign = interval_sign(span);
+
+		if (isign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor * isign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3615,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3651,33 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "infinity / infinity" as an error, since the interval type has
+	 * nothing equivalent to NaN.  Otherwise, dividing by infinity is handled
+	 * by the regular division code, causing all fields to be set to zero.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3699,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3466,11 +3727,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3493,11 +3764,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3524,11 +3805,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3547,161 +3838,387 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Functions to add or subtract finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
  */
+static void
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
+	state->N++;
+}
+
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle the to-be-discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_accum(PG_FUNCTION_ARGS)
+interval_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/*
+ * Combine function for sum() and avg() interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	if (state1 == NULL)
+	{
+		/* manually copy all fields from state2 to state1 */
+		state1 = makeIntervalAggState(fcinfo);
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	/* Accumulate finite interval values, if any. */
+	if (state2->N > 0)
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
+
+	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_serialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
 
-	Interval   *newsum;
-	ArrayType  *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+	pq_begintypsend(&buf);
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* N */
+	pq_sendint64(&buf, state->N);
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+	/* sumX */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	result = pq_endtypsend(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_BYTEA_P(result);
 }
 
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_deserialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	sstate = PG_GETARG_BYTEA_PP(0);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* N */
+	result->N = pq_getmsgint64(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* sumX */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
 }
 
+/*
+ * Inverse transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
+
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
+	{
+		Interval   *result;
+
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *result;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (state->pInfcount > 0)
+		INTERVAL_NOEND(result);
+	else if (state->nInfcount > 0)
+		INTERVAL_NOBEGIN(result);
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
+
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
@@ -3726,8 +4243,36 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4391,36 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4545,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4733,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4976,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5326,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5600,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5840,58 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5916,33 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval));
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +6185,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6422,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5783,7 +6465,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5806,13 +6487,18 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5864,7 +6550,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5888,13 +6573,18 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,13 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f14aed422a..d6a990e531 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,29 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum_inv' },
+{ oid => '8505', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '8506', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8507', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,6 +168,31 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 80801cd4ee..8f4c95b9e6 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -941,6 +941,34 @@ SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
          Index Cond: (a = '@ 30 years'::interval)
 (4 rows)
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+SET enable_seqscan = off;
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years ago'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years ago'::interval)
+(4 rows)
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years'::interval)
+(4 rows)
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index 8f52661096..cfb4b205e4 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1171,6 +1171,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1278,6 +1279,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1556,6 +1558,22 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1716,14 +1734,45 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1884,7 +1933,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..a481781475 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,8 +268,63 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
+
+-- test unary minus
+SELECT f1, -f1 FROM INTERVAL_TBL;
+       f1        |     ?column?      
+-----------------+-------------------
+ 00:01:00        | -00:01:00
+ 05:00:00        | -05:00:00
+ 10 days         | -10 days
+ 34 years        | -34 years
+ 3 mons          | -3 mons
+ -00:00:14       | 00:00:14
+ 1 day 02:03:04  | -1 days -02:03:04
+ 6 years         | -6 years
+ 5 mons          | -5 mons
+ 5 mons 12:00:00 | -5 mons -12:00:00
+ infinity        | -infinity
+ -infinity       | infinity
+(12 rows)
+
+SELECT -('-2147483648 months'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 months'::interval); -- ok
+        ?column?        
+------------------------
+ 178956970 years 7 mons
+(1 row)
+
+SELECT -('-2147483648 days'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 days'::interval); -- ok
+    ?column?     
+-----------------
+ 2147483647 days
+(1 row)
+
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-9223372036854775807 us'::interval); -- ok
+        ?column?         
+-------------------------
+ 2562047788:00:54.775807
+(1 row)
 
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+ERROR:  interval out of range
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -304,6 +391,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
@@ -386,12 +484,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +920,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +932,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1718,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1821,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1909,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1920,292 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
+(1 row)
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
+----------
+ infinity
+(1 row)
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT '-infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
@@ -1832,3 +2224,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  interval out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  interval out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,17 +2419,90 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2510,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2521,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,16 +2530,89 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2623,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2632,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,14 +2643,87 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2734,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2743,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,14 +2754,87 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2845,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2854,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,8 +2865,80 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -4375,6 +4752,52 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index b666dbad67..116106d30f 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -682,6 +682,25 @@ SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
 EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
 SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+
+SET enable_seqscan = off;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 39a35a6b7c..252bce4b1c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -213,10 +213,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -293,7 +295,6 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..caad291890 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -66,6 +70,17 @@ SELECT r1.*, r2.*
    WHERE r1.f1 > r2.f1
    ORDER BY r1.f1, r2.f1;
 
+-- test unary minus
+
+SELECT f1, -f1 FROM INTERVAL_TBL;
+SELECT -('-2147483648 months'::interval); -- should fail
+SELECT -('-2147483647 months'::interval); -- ok
+SELECT -('-2147483648 days'::interval); -- should fail
+SELECT -('-2147483647 days'::interval); -- ok
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+SELECT -('-9223372036854775807 us'::interval); -- ok
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -95,6 +110,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
@@ -140,7 +158,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -528,13 +546,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +616,157 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
@@ -605,3 +774,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,32 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +732,32 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +768,32 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +804,32 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +840,32 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,6 +1723,39 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 87c1aee379..236683e5ab 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3

From dbc3e01bbe79786c345e6c454bcfe583370098f2 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Sun, 5 Nov 2023 14:45:13 +0000
Subject: [PATCH v31 1/2] Avoid integer overflow hazard in interval_time().

When casting an interval to a time, the original code suffered from
64-bit integer overflow for inputs with a sufficiently large negative
"time" field, leading to bogus results.

Fix by rewriting the algorithm in a simpler form, that more obviously
cannot overflow. While at it, improve the test coverage to test
negative interval inputs.
---
 src/backend/utils/adt/date.c           | 15 +++------------
 src/test/regress/expected/horology.out | 12 ++++++++++++
 src/test/regress/sql/horology.sql      |  2 ++
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 56c7746c11..544e1d32bf 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2012,19 +2012,10 @@ interval_time(PG_FUNCTION_ARGS)
 {
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
-	int64		days;
 
-	result = span->time;
-	if (result >= USECS_PER_DAY)
-	{
-		days = result / USECS_PER_DAY;
-		result -= days * USECS_PER_DAY;
-	}
-	else if (result < 0)
-	{
-		days = (-result + USECS_PER_DAY - 1) / USECS_PER_DAY;
-		result += days * USECS_PER_DAY;
-	}
+	result = span->time % USECS_PER_DAY;
+	if (result < 0)
+		result += USECS_PER_DAY;
 
 	PG_RETURN_TIMEADT(result);
 }
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..8f52661096 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -981,6 +981,18 @@ SELECT CAST(interval '02:03' AS time) AS "02:03:00";
  02:03:00
 (1 row)
 
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+ 21:57:00 
+----------
+ 21:57:00
+(1 row)
+
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
+ 00:00:00 
+----------
+ 00:00:00
+(1 row)
+
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
  03:31:00 
 ----------
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..39a35a6b7c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -182,6 +182,8 @@ SELECT d1 - interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
 
 SELECT CAST(time '01:02' AS interval) AS "+01:02";
 SELECT CAST(interval '02:03' AS time) AS "02:03:00";
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
 SELECT time '01:30' - interval '02:01' AS "23:29:00";
 SELECT time '02:30' + interval '36:01' AS "14:31:00";
-- 
2.35.3

From 970fb377562a7bb1f2ca22c4e660312ec4f8cd45 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Mon, 6 Nov 2023 13:52:27 +0000
Subject: [PATCH v31 2/2] Support +/- infinity in the interval data type.

This adds support for infinity to the interval data type, using the
same input/output representation as the other date/time data types
that support infinity. This allows various arithmetic operations on
infinite dates, timestamps and intervals.

The new values are represented by setting all fields of the interval
to INT32/64_MIN for -infinity, and INT32/64_MAX for +infinity. This
ensures that they compare as less/greater than all other interval
values, without the need for any special-case comparison code.

Note that, since those 2 values were formerly accepted as legal finite
intervals, pg_upgrade and dump/restore from an old database will turn
them from finite to infinite intervals. That seems OK, since those
exact values should be extremely rare in practice, and they are
outside the documented range supported by the interval type, which
gives us a certain amount of leeway.

Joseph Koshakow, Jian He, and Ashutosh Bapat, reviewed by Dean Rasheed.

Discussion: https://postgr.es/m/CAAvxfHea4%2BsPybKK7agDYOMo9N-Z3J6ZXf3BOM79pFsFNcRjwA%40mail.gmail.com
---
 contrib/btree_gin/btree_gin.c             |    5 +-
 doc/src/sgml/datatype.sgml                |    4 +-
 doc/src/sgml/func.sgml                    |    8 +-
 src/backend/utils/adt/date.c              |   57 +-
 src/backend/utils/adt/datetime.c          |   26 +
 src/backend/utils/adt/formatting.c        |    2 +-
 src/backend/utils/adt/selfuncs.c          |    4 +
 src/backend/utils/adt/timestamp.c         | 1080 +++++++++++++++++----
 src/include/catalog/pg_aggregate.dat      |   24 +-
 src/include/catalog/pg_proc.dat           |   28 +-
 src/include/datatype/timestamp.h          |   27 +-
 src/test/regress/expected/brin_multi.out  |   28 +
 src/test/regress/expected/horology.out    |   71 +-
 src/test/regress/expected/interval.out    |  499 +++++++++-
 src/test/regress/expected/timestamp.out   |   62 ++
 src/test/regress/expected/timestamptz.out |   62 ++
 src/test/regress/expected/window.out      |  469 ++++++++-
 src/test/regress/sql/brin_multi.sql       |   19 +
 src/test/regress/sql/horology.sql         |    3 +-
 src/test/regress/sql/interval.sql         |  193 +++-
 src/test/regress/sql/timestamp.sql        |   19 +
 src/test/regress/sql/timestamptz.sql      |   18 +
 src/test/regress/sql/window.sql           |  167 +++-
 src/tools/pgindent/typedefs.list          |    1 +
 24 files changed, 2577 insertions(+), 299 deletions(-)

diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
index b09bb8df96..5e27906f80 100644
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,8 @@ leftmostvalue_interval(void)
 {
 	Interval   *v = palloc(sizeof(Interval));
 
-	v->time = PG_INT64_MIN;
-	v->day = PG_INT32_MIN;
-	v->month = PG_INT32_MIN;
+	INTERVAL_NOBEGIN(v);
+
 	return IntervalPGetDatum(v);
 }
 
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5a6cfbd94d..4aba6d19ee 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2328,12 +2328,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d963f0a0a0..146d71dd9f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9553,7 +9553,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10450,7 +10450,11 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 544e1d32bf..13745a0adc 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2013,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot convert infinite interval to time")));
+
 	result = span->time % USECS_PER_DAY;
 	if (result < 0)
 		result += USECS_PER_DAY;
@@ -2049,6 +2055,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2067,6 +2078,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2090,7 +2106,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2100,13 +2117,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2581,6 +2599,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2603,6 +2626,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -2630,7 +2658,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2640,13 +2669,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
@@ -3096,6 +3126,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3574,6 +3577,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -3597,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * Infinity cannot be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but using signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4802,6 +4802,10 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				 * Convert the month part of Interval to days using assumed
 				 * average month length of 365.25/12.0 days.  Not too
 				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
 				 */
 				return interval->time + interval->day * (double) USECS_PER_DAY +
 					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..54080e76b4 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -72,6 +72,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -80,6 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +962,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +992,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1384,10 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/* Typmod has no effect on infinite intervals */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1574,10 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	/* make sure that the result is finite */
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1602,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2015,6 +2068,9 @@ interval2itm(Interval span, struct pg_itm *itm)
 /* itm2interval()
  * Convert a pg_itm structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * This is for use in computations expected to produce finite results.  Any
+ * inputs that lead to infinite results are treated as overflows.
  */
 int
 itm2interval(struct pg_itm *itm, Interval *span)
@@ -2038,12 +2094,21 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2088,7 +2153,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2442,6 +2509,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2714,10 +2790,39 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
 	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt1))
+		{
+			if (TIMESTAMP_IS_NOBEGIN(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOBEGIN(result);
+		}
+		else if (TIMESTAMP_IS_NOEND(dt1))
+		{
+			if (TIMESTAMP_IS_NOEND(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOEND(result);
+		}
+		else if (TIMESTAMP_IS_NOBEGIN(dt2))
+			INTERVAL_NOEND(result);
+		else					/* TIMESTAMP_IS_NOEND(dt2) */
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
 
 	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
 		ereport(ERROR,
@@ -2783,6 +2888,10 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2858,6 +2967,10 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2896,6 +3009,10 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2934,7 +3051,31 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamp type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3181,31 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamptz type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3295,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3346,29 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* interval_um_internal()
+ * Negate an interval.
+ */
+static void
+interval_um_internal(const Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		/* Negate each field, guarding against overflow */
+		if (pg_sub_s64_overflow(INT64CONST(0), interval->time, &result->time) ||
+			pg_sub_s32_overflow(0, interval->day, &result->day) ||
+			pg_sub_s32_overflow(0, interval->month, &result->month) ||
+			INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3376,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3420,34 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3461,36 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3515,46 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "0 * infinity" and "infinity * 0" as errors, since the
+	 * interval type has nothing equivalent to NaN.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+	if (isinf(factor))
+	{
+		int			isign = interval_sign(span);
+
+		if (isign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor * isign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3615,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3651,33 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "infinity / infinity" as an error, since the interval type has
+	 * nothing equivalent to NaN.  Otherwise, dividing by infinity is handled
+	 * by the regular division code, causing all fields to be set to zero.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3699,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3466,11 +3727,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3493,11 +3764,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3524,11 +3805,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3547,161 +3838,387 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Functions to add or subtract finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
  */
+static void
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
+	state->N++;
+}
+
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle the to-be-discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_accum(PG_FUNCTION_ARGS)
+interval_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/*
+ * Combine function for sum() and avg() interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	if (state1 == NULL)
+	{
+		/* manually copy all fields from state2 to state1 */
+		state1 = makeIntervalAggState(fcinfo);
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	/* Accumulate finite interval values, if any. */
+	if (state2->N > 0)
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
+
+	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_serialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
 
-	Interval   *newsum;
-	ArrayType  *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+	pq_begintypsend(&buf);
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* N */
+	pq_sendint64(&buf, state->N);
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+	/* sumX */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	result = pq_endtypsend(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_BYTEA_P(result);
 }
 
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_deserialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	sstate = PG_GETARG_BYTEA_PP(0);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* N */
+	result->N = pq_getmsgint64(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* sumX */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
 }
 
+/*
+ * Inverse transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
+
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
+	{
+		Interval   *result;
+
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *result;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (state->pInfcount > 0)
+		INTERVAL_NOEND(result);
+	else if (state->nInfcount > 0)
+		INTERVAL_NOBEGIN(result);
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
+
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
@@ -3726,8 +4243,36 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4391,36 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4545,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4733,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4976,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5326,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5600,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5840,58 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5916,33 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval));
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +6185,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6422,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5783,7 +6465,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5806,13 +6487,18 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5864,7 +6550,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5888,13 +6573,18 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,13 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f14aed422a..d6a990e531 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,29 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum_inv' },
+{ oid => '8505', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '8506', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8507', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,6 +168,31 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 80801cd4ee..8f4c95b9e6 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -941,6 +941,34 @@ SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
          Index Cond: (a = '@ 30 years'::interval)
 (4 rows)
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+SET enable_seqscan = off;
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years ago'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years ago'::interval)
+(4 rows)
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years'::interval)
+(4 rows)
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index 8f52661096..cfb4b205e4 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1171,6 +1171,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1278,6 +1279,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1556,6 +1558,22 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1716,14 +1734,45 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1884,7 +1933,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..a481781475 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,8 +268,63 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
+
+-- test unary minus
+SELECT f1, -f1 FROM INTERVAL_TBL;
+       f1        |     ?column?      
+-----------------+-------------------
+ 00:01:00        | -00:01:00
+ 05:00:00        | -05:00:00
+ 10 days         | -10 days
+ 34 years        | -34 years
+ 3 mons          | -3 mons
+ -00:00:14       | 00:00:14
+ 1 day 02:03:04  | -1 days -02:03:04
+ 6 years         | -6 years
+ 5 mons          | -5 mons
+ 5 mons 12:00:00 | -5 mons -12:00:00
+ infinity        | -infinity
+ -infinity       | infinity
+(12 rows)
+
+SELECT -('-2147483648 months'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 months'::interval); -- ok
+        ?column?        
+------------------------
+ 178956970 years 7 mons
+(1 row)
+
+SELECT -('-2147483648 days'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 days'::interval); -- ok
+    ?column?     
+-----------------
+ 2147483647 days
+(1 row)
+
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-9223372036854775807 us'::interval); -- ok
+        ?column?         
+-------------------------
+ 2562047788:00:54.775807
+(1 row)
 
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+ERROR:  interval out of range
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -304,6 +391,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
@@ -386,12 +484,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +920,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +932,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1718,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1821,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1909,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1920,292 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
+(1 row)
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
+----------
+ infinity
+(1 row)
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT '-infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
@@ -1832,3 +2224,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  interval out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  interval out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,17 +2419,90 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2510,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2521,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,16 +2530,89 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2623,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2632,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,14 +2643,87 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2734,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2743,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,14 +2754,87 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2845,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2854,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,8 +2865,80 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -4375,6 +4752,52 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index b666dbad67..116106d30f 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -682,6 +682,25 @@ SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
 EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
 SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+
+SET enable_seqscan = off;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 39a35a6b7c..252bce4b1c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -213,10 +213,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -293,7 +295,6 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..caad291890 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -66,6 +70,17 @@ SELECT r1.*, r2.*
    WHERE r1.f1 > r2.f1
    ORDER BY r1.f1, r2.f1;
 
+-- test unary minus
+
+SELECT f1, -f1 FROM INTERVAL_TBL;
+SELECT -('-2147483648 months'::interval); -- should fail
+SELECT -('-2147483647 months'::interval); -- ok
+SELECT -('-2147483648 days'::interval); -- should fail
+SELECT -('-2147483647 days'::interval); -- ok
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+SELECT -('-9223372036854775807 us'::interval); -- ok
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -95,6 +110,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
@@ -140,7 +158,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -528,13 +546,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +616,157 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
@@ -605,3 +774,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,32 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +732,32 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +768,32 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +804,32 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +840,32 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,6 +1723,39 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 87c1aee379..236683e5ab 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3

From 3117b2d53261ae0414b4dcdfad1d960d4f5a0256 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Sun, 5 Nov 2023 14:45:13 +0000
Subject: [PATCH 2/3] Avoid integer overflow hazard in interval_time().

When casting an interval to a time, the original code suffered from
64-bit integer overflow for inputs with a sufficiently large negative
"time" field, leading to bogus results.

Fix by rewriting the algorithm in a simpler form, that more obviously
cannot overflow. While at it, improve the test coverage to test
negative interval inputs.
---
 src/backend/utils/adt/date.c           | 15 +++------------
 src/test/regress/expected/horology.out | 12 ++++++++++++
 src/test/regress/sql/horology.sql      |  2 ++
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 56c7746c11..544e1d32bf 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -2012,19 +2012,10 @@ interval_time(PG_FUNCTION_ARGS)
 {
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
-	int64		days;
 
-	result = span->time;
-	if (result >= USECS_PER_DAY)
-	{
-		days = result / USECS_PER_DAY;
-		result -= days * USECS_PER_DAY;
-	}
-	else if (result < 0)
-	{
-		days = (-result + USECS_PER_DAY - 1) / USECS_PER_DAY;
-		result += days * USECS_PER_DAY;
-	}
+	result = span->time % USECS_PER_DAY;
+	if (result < 0)
+		result += USECS_PER_DAY;
 
 	PG_RETURN_TIMEADT(result);
 }
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index e63e5b30fe..8f52661096 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -981,6 +981,18 @@ SELECT CAST(interval '02:03' AS time) AS "02:03:00";
  02:03:00
 (1 row)
 
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+ 21:57:00 
+----------
+ 21:57:00
+(1 row)
+
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
+ 00:00:00 
+----------
+ 00:00:00
+(1 row)
+
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
  03:31:00 
 ----------
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index f7f8c8d2dd..39a35a6b7c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -182,6 +182,8 @@ SELECT d1 - interval '1 year' AS one_year FROM TIMESTAMPTZ_TBL;
 
 SELECT CAST(time '01:02' AS interval) AS "+01:02";
 SELECT CAST(interval '02:03' AS time) AS "02:03:00";
+SELECT CAST(interval '-02:03' AS time) AS "21:57:00";
+SELECT CAST(interval '-9223372022400000000 us' AS time) AS "00:00:00";
 SELECT time '01:30' + interval '02:01' AS "03:31:00";
 SELECT time '01:30' - interval '02:01' AS "23:29:00";
 SELECT time '02:30' + interval '36:01' AS "14:31:00";
-- 
2.25.1

From e921eb52650d59847af81cc2f1b8a197ad3811cd Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Date: Thu, 9 Nov 2023 12:27:20 +0530
Subject: [PATCH 1/3] Fix integer overflow in pg_sub_s64_overflow()

Dean Rasheed's patch as is
---
 src/include/common/int.h           | 6 +++++-
 src/test/regress/expected/int8.out | 2 ++
 src/test/regress/sql/int8.sql      | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/include/common/int.h b/src/include/common/int.h
index 450800894e..487124473d 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -200,8 +200,12 @@ pg_sub_s64_overflow(int64 a, int64 b, int64 *result)
 	*result = (int64) res;
 	return false;
 #else
+	/*
+	 * Note: overflow is also possible when a == 0 and b < 0 (specifically,
+	 * when b == PG_INT64_MIN).
+	 */
 	if ((a < 0 && b > 0 && a < PG_INT64_MIN + b) ||
-		(a > 0 && b < 0 && a > PG_INT64_MAX + b))
+		(a >= 0 && b < 0 && a > PG_INT64_MAX + b))
 	{
 		*result = 0x5EED;		/* to avoid spurious warnings */
 		return true;
diff --git a/src/test/regress/expected/int8.out b/src/test/regress/expected/int8.out
index 9542d622ba..fddc09f630 100644
--- a/src/test/regress/expected/int8.out
+++ b/src/test/regress/expected/int8.out
@@ -679,6 +679,8 @@ select -('-9223372036854775807'::int8);
 
 select -('-9223372036854775808'::int8);
 ERROR:  bigint out of range
+select 0::int8 - '-9223372036854775808'::int8;
+ERROR:  bigint out of range
 select '9223372036854775800'::int8 + '9223372036854775800'::int8;
 ERROR:  bigint out of range
 select '-9223372036854775800'::int8 + '-9223372036854775800'::int8;
diff --git a/src/test/regress/sql/int8.sql b/src/test/regress/sql/int8.sql
index 33f664dd02..fffb28906a 100644
--- a/src/test/regress/sql/int8.sql
+++ b/src/test/regress/sql/int8.sql
@@ -132,6 +132,7 @@ select '9223372036854775808'::int8;
 
 select -('-9223372036854775807'::int8);
 select -('-9223372036854775808'::int8);
+select 0::int8 - '-9223372036854775808'::int8;
 
 select '9223372036854775800'::int8 + '9223372036854775800'::int8;
 select '-9223372036854775800'::int8 + '-9223372036854775800'::int8;
-- 
2.25.1

From 837d2f6f1af7a38f189c875428140b1174d77783 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Mon, 6 Nov 2023 13:52:27 +0000
Subject: [PATCH 3/3] Support +/- infinity in the interval data type.

This adds support for infinity to the interval data type, using the
same input/output representation as the other date/time data types
that support infinity. This allows various arithmetic operations on
infinite dates, timestamps and intervals.

The new values are represented by setting all fields of the interval
to INT32/64_MIN for -infinity, and INT32/64_MAX for +infinity. This
ensures that they compare as less/greater than all other interval
values, without the need for any special-case comparison code.

Note that, since those 2 values were formerly accepted as legal finite
intervals, pg_upgrade and dump/restore from an old database will turn
them from finite to infinite intervals. That seems OK, since those
exact values should be extremely rare in practice, and they are
outside the documented range supported by the interval type, which
gives us a certain amount of leeway.

Joseph Koshakow, Jian He, and Ashutosh Bapat, reviewed by Dean Rasheed.

Discussion: https://postgr.es/m/CAAvxfHea4%2BsPybKK7agDYOMo9N-Z3J6ZXf3BOM79pFsFNcRjwA%40mail.gmail.com
---
 contrib/btree_gin/btree_gin.c             |    5 +-
 doc/src/sgml/datatype.sgml                |    4 +-
 doc/src/sgml/func.sgml                    |    8 +-
 src/backend/utils/adt/date.c              |   57 +-
 src/backend/utils/adt/datetime.c          |   26 +
 src/backend/utils/adt/formatting.c        |    2 +-
 src/backend/utils/adt/selfuncs.c          |    4 +
 src/backend/utils/adt/timestamp.c         | 1080 +++++++++++++++++----
 src/include/catalog/pg_aggregate.dat      |   24 +-
 src/include/catalog/pg_proc.dat           |   28 +-
 src/include/datatype/timestamp.h          |   27 +-
 src/test/regress/expected/brin_multi.out  |   28 +
 src/test/regress/expected/horology.out    |   71 +-
 src/test/regress/expected/interval.out    |  499 +++++++++-
 src/test/regress/expected/timestamp.out   |   62 ++
 src/test/regress/expected/timestamptz.out |   62 ++
 src/test/regress/expected/window.out      |  469 ++++++++-
 src/test/regress/sql/brin_multi.sql       |   19 +
 src/test/regress/sql/horology.sql         |    3 +-
 src/test/regress/sql/interval.sql         |  193 +++-
 src/test/regress/sql/timestamp.sql        |   19 +
 src/test/regress/sql/timestamptz.sql      |   18 +
 src/test/regress/sql/window.sql           |  167 +++-
 src/tools/pgindent/typedefs.list          |    1 +
 24 files changed, 2577 insertions(+), 299 deletions(-)

diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
index b09bb8df96..5e27906f80 100644
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,8 @@ leftmostvalue_interval(void)
 {
 	Interval   *v = palloc(sizeof(Interval));
 
-	v->time = PG_INT64_MIN;
-	v->day = PG_INT32_MIN;
-	v->month = PG_INT32_MIN;
+	INTERVAL_NOBEGIN(v);
+
 	return IntervalPGetDatum(v);
 }
 
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5a6cfbd94d..4aba6d19ee 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2328,12 +2328,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d963f0a0a0..146d71dd9f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9553,7 +9553,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10450,7 +10450,11 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 544e1d32bf..13745a0adc 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2013,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot convert infinite interval to time")));
+
 	result = span->time % USECS_PER_DAY;
 	if (result < 0)
 		result += USECS_PER_DAY;
@@ -2049,6 +2055,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2067,6 +2078,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2090,7 +2106,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2100,13 +2117,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2581,6 +2599,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2603,6 +2626,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -2630,7 +2658,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2640,13 +2669,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
@@ -3096,6 +3126,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3574,6 +3577,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -3597,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * Infinity cannot be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but using signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4802,6 +4802,10 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				 * Convert the month part of Interval to days using assumed
 				 * average month length of 365.25/12.0 days.  Not too
 				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
 				 */
 				return interval->time + interval->day * (double) USECS_PER_DAY +
 					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..54080e76b4 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -72,6 +72,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -80,6 +95,12 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
+static void finite_interval_pl(const Interval *span1, const Interval *span2,
+							   Interval *result);
+static void finite_interval_mi(const Interval *span1, const Interval *span2,
+							   Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +962,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +992,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1384,10 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/* Typmod has no effect on infinite intervals */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1574,10 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	/* make sure that the result is finite */
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1602,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2015,6 +2068,9 @@ interval2itm(Interval span, struct pg_itm *itm)
 /* itm2interval()
  * Convert a pg_itm structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * This is for use in computations expected to produce finite results.  Any
+ * inputs that lead to infinite results are treated as overflows.
  */
 int
 itm2interval(struct pg_itm *itm, Interval *span)
@@ -2038,12 +2094,21 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2088,7 +2153,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2442,6 +2509,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2714,10 +2790,39 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
 	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt1))
+		{
+			if (TIMESTAMP_IS_NOBEGIN(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOBEGIN(result);
+		}
+		else if (TIMESTAMP_IS_NOEND(dt1))
+		{
+			if (TIMESTAMP_IS_NOEND(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOEND(result);
+		}
+		else if (TIMESTAMP_IS_NOBEGIN(dt2))
+			INTERVAL_NOEND(result);
+		else					/* TIMESTAMP_IS_NOEND(dt2) */
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
 
 	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
 		ereport(ERROR,
@@ -2783,6 +2888,10 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2858,6 +2967,10 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2896,6 +3009,10 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2934,7 +3051,31 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamp type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3154,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3181,31 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamptz type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3295,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3346,29 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* interval_um_internal()
+ * Negate an interval.
+ */
+static void
+interval_um_internal(const Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		/* Negate each field, guarding against overflow */
+		if (pg_sub_s64_overflow(INT64CONST(0), interval->time, &result->time) ||
+			pg_sub_s32_overflow(0, interval->day, &result->day) ||
+			pg_sub_s32_overflow(0, interval->month, &result->month) ||
+			INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3376,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3252,27 +3420,34 @@ interval_pl(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+		finite_interval_pl(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3286,27 +3461,36 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3515,46 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "0 * infinity" and "infinity * 0" as errors, since the
+	 * interval type has nothing equivalent to NaN.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+	if (isinf(factor))
+	{
+		int			isign = interval_sign(span);
+
+		if (isign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor * isign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3615,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3651,33 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "infinity / infinity" as an error, since the interval type has
+	 * nothing equivalent to NaN.  Otherwise, dividing by infinity is handled
+	 * by the regular division code, causing all fields to be set to zero.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3699,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3466,11 +3727,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3493,11 +3764,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3524,11 +3805,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3547,161 +3838,387 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
+ *
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Functions to add or subtract finite intervals.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * These are used for normal arithmetic and aggregation of finite intervals
+ * only.  Non-finite intervals require special handling.
  */
+static void
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+static void
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
+	state->N++;
+}
+
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle the to-be-discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_accum(PG_FUNCTION_ARGS)
+interval_avg_accum(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	PG_RETURN_POINTER(state);
+}
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+/*
+ * Combine function for sum() and avg() interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
+ */
+Datum
+interval_avg_combine(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state1;
+	IntervalAggState *state2;
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
+
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
+
+	if (state1 == NULL)
+	{
+		/* manually copy all fields from state2 to state1 */
+		state1 = makeIntervalAggState(fcinfo);
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
+
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
+
+		PG_RETURN_POINTER(state1);
+	}
+
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
+
+	/* Accumulate finite interval values, if any. */
+	if (state2->N > 0)
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
+
+	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_serialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
 
-	Interval   *newsum;
-	ArrayType  *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+	pq_begintypsend(&buf);
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* N */
+	pq_sendint64(&buf, state->N);
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+	/* sumX */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	result = pq_endtypsend(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_BYTEA_P(result);
 }
 
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_deserialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	sstate = PG_GETARG_BYTEA_PP(0);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* N */
+	result->N = pq_getmsgint64(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* sumX */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
+
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
+
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
 }
 
+/*
+ * Inverse transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
+
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
+	{
+		Interval   *result;
+
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *result;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (state->pInfcount > 0)
+		INTERVAL_NOEND(result);
+	else if (state->nInfcount > 0)
+		INTERVAL_NOBEGIN(result);
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
+
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
@@ -3726,8 +4243,36 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4391,36 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4545,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4733,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4976,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5326,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5600,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5840,58 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5916,33 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval));
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +6185,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6422,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5783,7 +6465,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5806,13 +6487,18 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5864,7 +6550,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5888,13 +6573,18 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,13 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f14aed422a..d6a990e531 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,29 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum_inv' },
+{ oid => '8505', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '8506', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8507', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,6 +168,31 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 80801cd4ee..8f4c95b9e6 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -941,6 +941,34 @@ SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
          Index Cond: (a = '@ 30 years'::interval)
 (4 rows)
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+SET enable_seqscan = off;
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years ago'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years ago'::interval)
+(4 rows)
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years'::interval)
+(4 rows)
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index 8f52661096..cfb4b205e4 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1171,6 +1171,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1278,6 +1279,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1556,6 +1558,22 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1716,14 +1734,45 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1884,7 +1933,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..a481781475 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,8 +268,63 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
+
+-- test unary minus
+SELECT f1, -f1 FROM INTERVAL_TBL;
+       f1        |     ?column?      
+-----------------+-------------------
+ 00:01:00        | -00:01:00
+ 05:00:00        | -05:00:00
+ 10 days         | -10 days
+ 34 years        | -34 years
+ 3 mons          | -3 mons
+ -00:00:14       | 00:00:14
+ 1 day 02:03:04  | -1 days -02:03:04
+ 6 years         | -6 years
+ 5 mons          | -5 mons
+ 5 mons 12:00:00 | -5 mons -12:00:00
+ infinity        | -infinity
+ -infinity       | infinity
+(12 rows)
+
+SELECT -('-2147483648 months'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 months'::interval); -- ok
+        ?column?        
+------------------------
+ 178956970 years 7 mons
+(1 row)
+
+SELECT -('-2147483648 days'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 days'::interval); -- ok
+    ?column?     
+-----------------
+ 2147483647 days
+(1 row)
+
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-9223372036854775807 us'::interval); -- ok
+        ?column?         
+-------------------------
+ 2562047788:00:54.775807
+(1 row)
 
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+ERROR:  interval out of range
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -304,6 +391,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
@@ -386,12 +484,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +920,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +932,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1718,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1821,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1909,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1920,292 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
+(1 row)
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
+----------
+ infinity
+(1 row)
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT '-infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
@@ -1832,3 +2224,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  interval out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  interval out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,17 +2419,90 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2510,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2521,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,16 +2530,89 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2623,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2632,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,14 +2643,87 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2734,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2743,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,14 +2754,87 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2845,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2854,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,8 +2865,80 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -4375,6 +4752,52 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index b666dbad67..116106d30f 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -682,6 +682,25 @@ SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
 EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
 SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+
+SET enable_seqscan = off;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 39a35a6b7c..252bce4b1c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -213,10 +213,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -293,7 +295,6 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..caad291890 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -66,6 +70,17 @@ SELECT r1.*, r2.*
    WHERE r1.f1 > r2.f1
    ORDER BY r1.f1, r2.f1;
 
+-- test unary minus
+
+SELECT f1, -f1 FROM INTERVAL_TBL;
+SELECT -('-2147483648 months'::interval); -- should fail
+SELECT -('-2147483647 months'::interval); -- ok
+SELECT -('-2147483648 days'::interval); -- should fail
+SELECT -('-2147483647 days'::interval); -- ok
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+SELECT -('-9223372036854775807 us'::interval); -- ok
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -95,6 +110,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
@@ -140,7 +158,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -528,13 +546,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +616,157 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
@@ -605,3 +774,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,32 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +732,32 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +768,32 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +804,32 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +840,32 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,6 +1723,39 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index bf50a32119..efc47bed10 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.25.1

From a8b210f01d31337b6bf074741af7c221df35fc67 Mon Sep 17 00:00:00 2001
From: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: Mon, 6 Nov 2023 13:52:27 +0000
Subject: [PATCH v32] Support +/- infinity in the interval data type.

This adds support for infinity to the interval data type, using the
same input/output representation as the other date/time data types
that support infinity. This allows various arithmetic operations on
infinite dates, timestamps and intervals.

The new values are represented by setting all fields of the interval
to INT32/64_MIN for -infinity, and INT32/64_MAX for +infinity. This
ensures that they compare as less/greater than all other interval
values, without the need for any special-case comparison code.

Note that, since those 2 values were formerly accepted as legal finite
intervals, pg_upgrade and dump/restore from an old database will turn
them from finite to infinite intervals. That seems OK, since those
exact values should be extremely rare in practice, and they are
outside the documented range supported by the interval type, which
gives us a certain amount of leeway.

Joseph Koshakow, Jian He, and Ashutosh Bapat, reviewed by Dean Rasheed.

Discussion: https://postgr.es/m/CAAvxfHea4%2BsPybKK7agDYOMo9N-Z3J6ZXf3BOM79pFsFNcRjwA%40mail.gmail.com
---
 contrib/btree_gin/btree_gin.c             |    5 +-
 doc/src/sgml/datatype.sgml                |    4 +-
 doc/src/sgml/func.sgml                    |    8 +-
 src/backend/utils/adt/date.c              |   57 +-
 src/backend/utils/adt/datetime.c          |   26 +
 src/backend/utils/adt/formatting.c        |    2 +-
 src/backend/utils/adt/selfuncs.c          |    4 +
 src/backend/utils/adt/timestamp.c         | 1044 +++++++++++++++++----
 src/include/catalog/pg_aggregate.dat      |   24 +-
 src/include/catalog/pg_proc.dat           |   28 +-
 src/include/datatype/timestamp.h          |   27 +-
 src/test/regress/expected/brin_multi.out  |   28 +
 src/test/regress/expected/horology.out    |   71 +-
 src/test/regress/expected/interval.out    |  499 +++++++++-
 src/test/regress/expected/timestamp.out   |   62 ++
 src/test/regress/expected/timestamptz.out |   62 ++
 src/test/regress/expected/window.out      |  469 ++++++++-
 src/test/regress/sql/brin_multi.sql       |   19 +
 src/test/regress/sql/horology.sql         |    3 +-
 src/test/regress/sql/interval.sql         |  193 +++-
 src/test/regress/sql/timestamp.sql        |   19 +
 src/test/regress/sql/timestamptz.sql      |   18 +
 src/test/regress/sql/window.sql           |  167 +++-
 src/tools/pgindent/typedefs.list          |    1 +
 24 files changed, 2554 insertions(+), 286 deletions(-)

diff --git a/contrib/btree_gin/btree_gin.c b/contrib/btree_gin/btree_gin.c
index b09bb8df96..5e27906f80 100644
--- a/contrib/btree_gin/btree_gin.c
+++ b/contrib/btree_gin/btree_gin.c
@@ -306,9 +306,8 @@ leftmostvalue_interval(void)
 {
 	Interval   *v = palloc(sizeof(Interval));
 
-	v->time = PG_INT64_MIN;
-	v->day = PG_INT32_MIN;
-	v->month = PG_INT32_MIN;
+	INTERVAL_NOBEGIN(v);
+
 	return IntervalPGetDatum(v);
 }
 
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 5a6cfbd94d..4aba6d19ee 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -2328,12 +2328,12 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
          </row>
          <row>
           <entry><literal>infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>later than all other time stamps</entry>
          </row>
          <row>
           <entry><literal>-infinity</literal></entry>
-          <entry><type>date</type>, <type>timestamp</type></entry>
+          <entry><type>date</type>, <type>timestamp</type>, <type>interval</type></entry>
           <entry>earlier than all other time stamps</entry>
          </row>
          <row>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index d963f0a0a0..146d71dd9f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9553,7 +9553,7 @@ SELECT regexp_match('abc01234xyz', '(?:(.*?)(\d+)(.*)){1,1}');
          <returnvalue>boolean</returnvalue>
         </para>
         <para>
-         Test for finite interval (currently always true)
+         Test for finite interval (not +/-infinity)
         </para>
         <para>
          <literal>isfinite(interval '4 hours')</literal>
@@ -10450,7 +10450,11 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
      When the input value is +/-Infinity, <function>extract</function> returns
      +/-Infinity for monotonically-increasing fields (<literal>epoch</literal>,
      <literal>julian</literal>, <literal>year</literal>, <literal>isoyear</literal>,
-     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>).
+     <literal>decade</literal>, <literal>century</literal>, and <literal>millennium</literal>
+     for <type>timestamp</type> inputs; <literal>epoch</literal>, <literal>hour</literal>,
+     <literal>day</literal>, <literal>year</literal>, <literal>decade</literal>,
+     <literal>century</literal>, and <literal>millennium</literal> for
+     <type>interval</type> inputs).
      For other fields, NULL is returned.  <productname>PostgreSQL</productname>
      versions before 9.6 returned zero for all cases of infinite input.
     </para>
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 544e1d32bf..13745a0adc 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -24,6 +24,7 @@
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/supportnodes.h"
@@ -2013,6 +2014,11 @@ interval_time(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(0);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot convert infinite interval to time")));
+
 	result = span->time % USECS_PER_DAY;
 	if (result < 0)
 		result += USECS_PER_DAY;
@@ -2049,6 +2055,11 @@ time_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = time + span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2067,6 +2078,11 @@ time_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeADT		result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = time - span->time;
 	result -= result / USECS_PER_DAY * USECS_PER_DAY;
 	if (result < INT64CONST(0))
@@ -2090,7 +2106,8 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like time_pl_interval/time_mi_interval, we disregard the month and day
-	 * fields of the offset.  So our test for negative should too.
+	 * fields of the offset.  So our test for negative should too.  This also
+	 * catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2100,13 +2117,14 @@ in_range_time_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use time_pl_interval/time_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum = base - offset->time;
-	else
-		sum = base + offset->time;
+	else if (pg_add_s64_overflow(base, offset->time, &sum))
+		PG_RETURN_BOOL(less);
 
 	if (less)
 		PG_RETURN_BOOL(val <= sum);
@@ -2581,6 +2599,11 @@ timetz_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot add infinite interval to time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time + span->time;
@@ -2603,6 +2626,11 @@ timetz_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	TimeTzADT  *result;
 
+	if (INTERVAL_NOT_FINITE(span))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("cannot subtract infinite interval from time")));
+
 	result = (TimeTzADT *) palloc(sizeof(TimeTzADT));
 
 	result->time = time->time - span->time;
@@ -2630,7 +2658,8 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 
 	/*
 	 * Like timetz_pl_interval/timetz_mi_interval, we disregard the month and
-	 * day fields of the offset.  So our test for negative should too.
+	 * day fields of the offset.  So our test for negative should too. This
+	 * also catches -infinity, so we only need worry about +infinity below.
 	 */
 	if (offset->time < 0)
 		ereport(ERROR,
@@ -2640,13 +2669,14 @@ in_range_timetz_interval(PG_FUNCTION_ARGS)
 	/*
 	 * We can't use timetz_pl_interval/timetz_mi_interval here, because their
 	 * wraparound behavior would give wrong (or at least undesirable) answers.
-	 * Fortunately the equivalent non-wrapping behavior is trivial, especially
-	 * since we don't worry about integer overflow.
+	 * Fortunately the equivalent non-wrapping behavior is trivial, except
+	 * that adding an infinite (or very large) interval might cause integer
+	 * overflow.  Subtraction cannot overflow here.
 	 */
 	if (sub)
 		sum.time = base->time - offset->time;
-	else
-		sum.time = base->time + offset->time;
+	else if (pg_add_s64_overflow(base->time, offset->time, &sum.time))
+		PG_RETURN_BOOL(less);
 	sum.zone = base->zone;
 
 	if (less)
@@ -3096,6 +3126,13 @@ timetz_izone(PG_FUNCTION_ARGS)
 	TimeTzADT  *result;
 	int			tz;
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 267dfd37b2..fca9a2a6e9 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -3271,6 +3271,9 @@ ClearPgItmIn(struct pg_itm_in *itm_in)
  *
  * Allow ISO-style time span, with implicit units on number of days
  *	preceding an hh:mm:ss field. - thomas 1998-04-30
+ *
+ * itm_in remains undefined for infinite interval values for which dtype alone
+ * suffices.
  */
 int
 DecodeInterval(char **field, int *ftype, int nf, int range,
@@ -3574,6 +3577,8 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 				if (parsing_unit_val)
 					return DTERR_BAD_FORMAT;
 				type = DecodeUnits(i, field[i], &uval);
+				if (type == UNKNOWN_FIELD)
+					type = DecodeSpecial(i, field[i], &uval);
 				if (type == IGNORE_DTF)
 					continue;
 
@@ -3597,6 +3602,27 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
 						type = uval;
 						break;
 
+					case RESERV:
+						tmask = (DTK_DATE_M | DTK_TIME_M);
+
+						/*
+						 * Only reserved words corresponding to infinite
+						 * intervals are accepted.
+						 */
+						if (uval != DTK_LATE && uval != DTK_EARLY)
+							return DTERR_BAD_FORMAT;
+
+						/*
+						 * Infinity cannot be followed by anything else. We
+						 * could allow "ago" to reverse the sign of infinity
+						 * but using signed infinity is more intuitive.
+						 */
+						if (i != nf - 1)
+							return DTERR_BAD_FORMAT;
+
+						*dtype = uval;
+						break;
+
 					default:
 						return DTERR_BAD_FORMAT;
 				}
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8131091f79..d176723d95 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4127,7 +4127,7 @@ interval_to_char(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *itm = &tt;
 
-	if (VARSIZE_ANY_EXHDR(fmt) <= 0)
+	if (VARSIZE_ANY_EXHDR(fmt) <= 0 || INTERVAL_NOT_FINITE(it))
 		PG_RETURN_NULL();
 
 	ZERO_tmtc(&tmtc);
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index c4fcd0076e..4ea5415f20 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4802,6 +4802,10 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				 * Convert the month part of Interval to days using assumed
 				 * average month length of 365.25/12.0 days.  Not too
 				 * accurate, but plenty good enough for our purposes.
+				 *
+				 * This also works for infinite intervals, which just have all
+				 * fields set to INT_MIN/INT_MAX, and so will produce a result
+				 * smaller/larger than any finite interval.
 				 */
 				return interval->time + interval->day * (double) USECS_PER_DAY +
 					interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 647b97aca6..b53bf47786 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -72,6 +72,21 @@ typedef struct
 	pg_tz	   *attimezone;
 } generate_series_timestamptz_fctx;
 
+/*
+ * The transition datatype for interval aggregates is declared as internal.
+ * It's a pointer to an IntervalAggState allocated in the aggregate context.
+ */
+typedef struct IntervalAggState
+{
+	int64		N;				/* count of finite intervals processed */
+	Interval	sumX;			/* sum of finite intervals processed */
+	/* These counts are *not* included in N!  Use IA_TOTAL_COUNT() as needed */
+	int64		pInfcount;		/* count of +infinity intervals */
+	int64		nInfcount;		/* count of -infinity intervals */
+} IntervalAggState;
+
+#define IA_TOTAL_COUNT(ia) \
+	((ia)->N + (ia)->pInfcount + (ia)->nInfcount)
 
 static TimeOffset time2t(const int hour, const int min, const int sec, const fsec_t fsec);
 static Timestamp dt2local(Timestamp dt, int timezone);
@@ -80,6 +95,8 @@ static bool AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 static TimestampTz timestamp2timestamptz(Timestamp timestamp);
 static Timestamp timestamptz2timestamp(TimestampTz timestamp);
 
+static void EncodeSpecialInterval(const Interval *interval, char *str);
+static void interval_um_internal(const Interval *interval, Interval *result);
 
 /* common code for timestamptypmodin and timestamptztypmodin */
 static int32
@@ -941,6 +958,14 @@ interval_in(PG_FUNCTION_ARGS)
 						 errmsg("interval out of range")));
 			break;
 
+		case DTK_LATE:
+			INTERVAL_NOEND(result);
+			break;
+
+		case DTK_EARLY:
+			INTERVAL_NOBEGIN(result);
+			break;
+
 		default:
 			elog(ERROR, "unexpected dtype %d while parsing interval \"%s\"",
 				 dtype, str);
@@ -963,8 +988,13 @@ interval_out(PG_FUNCTION_ARGS)
 			   *itm = &tt;
 	char		buf[MAXDATELEN + 1];
 
-	interval2itm(*span, itm);
-	EncodeInterval(itm, IntervalStyle, buf);
+	if (INTERVAL_NOT_FINITE(span))
+		EncodeSpecialInterval(span, buf);
+	else
+	{
+		interval2itm(*span, itm);
+		EncodeInterval(itm, IntervalStyle, buf);
+	}
 
 	result = pstrdup(buf);
 	PG_RETURN_CSTRING(result);
@@ -1350,6 +1380,10 @@ AdjustIntervalForTypmod(Interval *interval, int32 typmod,
 		INT64CONST(0)
 	};
 
+	/* Typmod has no effect on infinite intervals */
+	if (INTERVAL_NOT_FINITE(interval))
+		return true;
+
 	/*
 	 * Unspecified range and precision? Then not necessary to adjust. Setting
 	 * typmod to -1 is the convention for all data types.
@@ -1536,6 +1570,10 @@ make_interval(PG_FUNCTION_ARGS)
 		pg_add_s64_overflow(result->time, (int64) secs, &result->time))
 		goto out_of_range;
 
+	/* make sure that the result is finite */
+	if (INTERVAL_NOT_FINITE(result))
+		goto out_of_range;
+
 	PG_RETURN_INTERVAL_P(result);
 
 out_of_range:
@@ -1560,6 +1598,17 @@ EncodeSpecialTimestamp(Timestamp dt, char *str)
 		elog(ERROR, "invalid argument for EncodeSpecialTimestamp");
 }
 
+static void
+EncodeSpecialInterval(const Interval *interval, char *str)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		strcpy(str, EARLY);
+	else if (INTERVAL_IS_NOEND(interval))
+		strcpy(str, LATE);
+	else						/* shouldn't happen */
+		elog(ERROR, "invalid argument for EncodeSpecialInterval");
+}
+
 Datum
 now(PG_FUNCTION_ARGS)
 {
@@ -2015,6 +2064,9 @@ interval2itm(Interval span, struct pg_itm *itm)
 /* itm2interval()
  * Convert a pg_itm structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * This is for use in computations expected to produce finite results.  Any
+ * inputs that lead to infinite results are treated as overflows.
  */
 int
 itm2interval(struct pg_itm *itm, Interval *span)
@@ -2038,12 +2090,21 @@ itm2interval(struct pg_itm *itm, Interval *span)
 	if (pg_add_s64_overflow(span->time, itm->tm_usec,
 							&span->time))
 		return -1;
+	if (INTERVAL_NOT_FINITE(span))
+		return -1;
 	return 0;
 }
 
 /* itmin2interval()
  * Convert a pg_itm_in structure to an Interval.
  * Returns 0 if OK, -1 on overflow.
+ *
+ * Note: if the result is infinite, it is not treated as an overflow.  This
+ * avoids any dump/reload hazards from pre-17 databases that do not support
+ * infinite intervals, but do allow finite intervals with all fields set to
+ * INT_MIN/INT_MAX (outside the documented range).  Such intervals will be
+ * silently converted to +/-infinity.  This may not be ideal, but seems
+ * preferable to failure, and ought to be pretty unlikely in practice.
  */
 int
 itmin2interval(struct pg_itm_in *itm_in, Interval *span)
@@ -2088,7 +2149,9 @@ timestamp_finite(PG_FUNCTION_ARGS)
 Datum
 interval_finite(PG_FUNCTION_ARGS)
 {
-	PG_RETURN_BOOL(true);
+	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+
+	PG_RETURN_BOOL(!INTERVAL_NOT_FINITE(interval));
 }
 
 
@@ -2442,6 +2505,15 @@ interval_cmp_internal(const Interval *interval1, const Interval *interval2)
 	return int128_compare(span1, span2);
 }
 
+static int
+interval_sign(const Interval *interval)
+{
+	INT128		span = interval_cmp_value(interval);
+	INT128		zero = int64_to_int128(0);
+
+	return int128_compare(span, zero);
+}
+
 Datum
 interval_eq(PG_FUNCTION_ARGS)
 {
@@ -2714,10 +2786,39 @@ timestamp_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
 	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("cannot subtract infinite timestamps")));
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt1))
+		{
+			if (TIMESTAMP_IS_NOBEGIN(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOBEGIN(result);
+		}
+		else if (TIMESTAMP_IS_NOEND(dt1))
+		{
+			if (TIMESTAMP_IS_NOEND(dt2))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+						 errmsg("interval out of range")));
+			else
+				INTERVAL_NOEND(result);
+		}
+		else if (TIMESTAMP_IS_NOBEGIN(dt2))
+			INTERVAL_NOEND(result);
+		else					/* TIMESTAMP_IS_NOEND(dt2) */
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
 
 	if (unlikely(pg_sub_s64_overflow(dt1, dt2, &result->time)))
 		ereport(ERROR,
@@ -2783,6 +2884,10 @@ interval_justify_interval(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	/* pre-justify days if it might prevent overflow */
 	if ((result->day > 0 && result->time > 0) ||
 		(result->day < 0 && result->time < 0))
@@ -2858,6 +2963,10 @@ interval_justify_hours(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	TMODULO(result->time, wholeday, USECS_PER_DAY);
 	if (pg_add_s32_overflow(result->day, wholeday, &result->day))
 		ereport(ERROR,
@@ -2896,6 +3005,10 @@ interval_justify_days(PG_FUNCTION_ARGS)
 	result->day = span->day;
 	result->time = span->time;
 
+	/* do nothing for infinite intervals */
+	if (INTERVAL_NOT_FINITE(result))
+		PG_RETURN_INTERVAL_P(result);
+
 	wholemonth = result->day / DAYS_PER_MONTH;
 	result->day -= wholemonth * DAYS_PER_MONTH;
 	if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
@@ -2934,7 +3047,31 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Timestamp	result;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamp type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3013,9 +3150,7 @@ timestamp_mi_interval(PG_FUNCTION_ARGS)
 	Interval   *span = PG_GETARG_INTERVAL_P(1);
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return DirectFunctionCall2(timestamp_pl_interval,
 							   TimestampGetDatum(timestamp),
@@ -3042,7 +3177,31 @@ timestamptz_pl_interval_internal(TimestampTz timestamp,
 	TimestampTz result;
 	int			tz;
 
-	if (TIMESTAMP_NOT_FINITE(timestamp))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the timestamptz type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span))
+	{
+		if (TIMESTAMP_IS_NOEND(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(timestamp))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("timestamp out of range")));
+		else
+			TIMESTAMP_NOEND(result);
+	}
+	else if (TIMESTAMP_NOT_FINITE(timestamp))
 		result = timestamp;
 	else
 	{
@@ -3132,9 +3291,7 @@ timestamptz_mi_interval_internal(TimestampTz timestamp,
 {
 	Interval	tspan;
 
-	tspan.month = -span->month;
-	tspan.day = -span->day;
-	tspan.time = -span->time;
+	interval_um_internal(span, &tspan);
 
 	return timestamptz_pl_interval_internal(timestamp, &tspan, attimezone);
 }
@@ -3185,6 +3342,29 @@ timestamptz_mi_interval_at_zone(PG_FUNCTION_ARGS)
 	PG_RETURN_TIMESTAMP(timestamptz_mi_interval_internal(timestamp, span, attimezone));
 }
 
+/* interval_um_internal()
+ * Negate an interval.
+ */
+static void
+interval_um_internal(const Interval *interval, Interval *result)
+{
+	if (INTERVAL_IS_NOBEGIN(interval))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(interval))
+		INTERVAL_NOBEGIN(result);
+	else
+	{
+		/* Negate each field, guarding against overflow */
+		if (pg_sub_s64_overflow(INT64CONST(0), interval->time, &result->time) ||
+			pg_sub_s32_overflow(0, interval->day, &result->day) ||
+			pg_sub_s32_overflow(0, interval->month, &result->month) ||
+			INTERVAL_NOT_FINITE(result))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+	}
+}
+
 Datum
 interval_um(PG_FUNCTION_ARGS)
 {
@@ -3192,23 +3372,7 @@ interval_um(PG_FUNCTION_ARGS)
 	Interval   *result;
 
 	result = (Interval *) palloc(sizeof(Interval));
-
-	result->time = -interval->time;
-	/* overflow check copied from int4um */
-	if (interval->time != 0 && SAMESIGN(result->time, interval->time))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->day = -interval->day;
-	if (interval->day != 0 && SAMESIGN(result->day, interval->day))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
-	result->month = -interval->month;
-	if (interval->month != 0 && SAMESIGN(result->month, interval->month))
-		ereport(ERROR,
-				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range")));
+	interval_um_internal(interval, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3243,42 +3407,35 @@ interval_larger(PG_FUNCTION_ARGS)
 	PG_RETURN_INTERVAL_P(result);
 }
 
-Datum
-interval_pl(PG_FUNCTION_ARGS)
+static void
+finite_interval_pl(const Interval *span1, const Interval *span2, Interval *result)
 {
-	Interval   *span1 = PG_GETARG_INTERVAL_P(0);
-	Interval   *span2 = PG_GETARG_INTERVAL_P(1);
-	Interval   *result;
-
-	result = (Interval *) palloc(sizeof(Interval));
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
 
-	result->month = span1->month + span2->month;
-	/* overflow check copied from int4pl */
-	if (SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	if (pg_add_s32_overflow(span1->month, span2->month, &result->month))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->day = span1->day + span2->day;
-	if (SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
+	if (pg_add_s32_overflow(span1->day, span2->day, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->time = span1->time + span2->time;
-	if (SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	if (pg_add_s64_overflow(span1->time, span2->time, &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	PG_RETURN_INTERVAL_P(result);
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
 }
 
 Datum
-interval_mi(PG_FUNCTION_ARGS)
+interval_pl(PG_FUNCTION_ARGS)
 {
 	Interval   *span1 = PG_GETARG_INTERVAL_P(0);
 	Interval   *span2 = PG_GETARG_INTERVAL_P(1);
@@ -3286,27 +3443,104 @@ interval_mi(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	result->month = span1->month - span2->month;
-	/* overflow check copied from int4mi */
-	if (!SAMESIGN(span1->month, span2->month) &&
-		!SAMESIGN(result->month, span1->month))
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_NOT_FINITE(span2))
+		memcpy(result, span2, sizeof(Interval));
+	else
+		finite_interval_pl(span1, span2, result);
+
+	PG_RETURN_INTERVAL_P(result);
+}
+
+static void
+finite_interval_mi(const Interval *span1, const Interval *span2, Interval *result)
+{
+	Assert(!INTERVAL_NOT_FINITE(span1));
+	Assert(!INTERVAL_NOT_FINITE(span2));
+
+	if (pg_sub_s32_overflow(span1->month, span2->month, &result->month))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (pg_sub_s32_overflow(span1->day, span2->day, &result->day))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->day = span1->day - span2->day;
-	if (!SAMESIGN(span1->day, span2->day) &&
-		!SAMESIGN(result->day, span1->day))
+	if (pg_sub_s64_overflow(span1->time, span2->time, &result->time))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
 
-	result->time = span1->time - span2->time;
-	if (!SAMESIGN(span1->time, span2->time) &&
-		!SAMESIGN(result->time, span1->time))
+	if (INTERVAL_NOT_FINITE(result))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("interval out of range")));
+}
+
+Datum
+interval_mi(PG_FUNCTION_ARGS)
+{
+	Interval   *span1 = PG_GETARG_INTERVAL_P(0);
+	Interval   *span2 = PG_GETARG_INTERVAL_P(1);
+	Interval   *result;
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (INTERVAL_IS_NOBEGIN(span1))
+	{
+		if (INTERVAL_IS_NOBEGIN(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (INTERVAL_IS_NOEND(span1))
+	{
+		if (INTERVAL_IS_NOEND(span2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (INTERVAL_IS_NOBEGIN(span2))
+		INTERVAL_NOEND(result);
+	else if (INTERVAL_IS_NOEND(span2))
+		INTERVAL_NOBEGIN(result);
+	else
+		finite_interval_mi(span1, span2, result);
 
 	PG_RETURN_INTERVAL_P(result);
 }
@@ -3331,6 +3565,46 @@ interval_mul(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "0 * infinity" and "infinity * 0" as errors, since the
+	 * interval type has nothing equivalent to NaN.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (factor == 0.0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+	if (isinf(factor))
+	{
+		int			isign = interval_sign(span);
+
+		if (isign == 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else if (factor * isign < 0)
+			INTERVAL_NOBEGIN(result);
+		else
+			INTERVAL_NOEND(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result_double = span->month * factor;
 	if (isnan(result_double) ||
 		result_double > INT_MAX || result_double < INT_MIN)
@@ -3391,6 +3665,11 @@ interval_mul(PG_FUNCTION_ARGS)
 				 errmsg("interval out of range")));
 	result->time = (int64) result_double;
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3422,6 +3701,33 @@ interval_div(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
 
+	/*
+	 * Handle NaN and infinities.
+	 *
+	 * We treat "infinity / infinity" as an error, since the interval type has
+	 * nothing equivalent to NaN.  Otherwise, dividing by infinity is handled
+	 * by the regular division code, causing all fields to be set to zero.
+	 */
+	if (isnan(factor))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
+	if (INTERVAL_NOT_FINITE(span))
+	{
+		if (isinf(factor))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+
+		if (factor < 0.0)
+			interval_um_internal(span, result);
+		else
+			memcpy(result, span, sizeof(Interval));
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	result->month = (int32) (span->month / factor);
 	result->day = (int32) (span->day / factor);
 
@@ -3443,6 +3749,11 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day += (int32) month_remainder_days;
 	result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
 
+	if (INTERVAL_NOT_FINITE(result))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range")));
+
 	PG_RETURN_INTERVAL_P(result);
 }
 
@@ -3466,11 +3777,21 @@ in_range_timestamptz_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	TimestampTz sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = timestamptz_mi_interval_internal(base, offset, NULL);
@@ -3493,11 +3814,21 @@ in_range_timestamp_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Timestamp	sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? TIMESTAMP_IS_NOEND(base) : TIMESTAMP_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetTimestamp(DirectFunctionCall2(timestamp_mi_interval,
@@ -3524,11 +3855,21 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 	bool		less = PG_GETARG_BOOL(4);
 	Interval   *sum;
 
-	if (int128_compare(interval_cmp_value(offset), int64_to_int128(0)) < 0)
+	if (interval_sign(offset) < 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
 				 errmsg("invalid preceding or following size in window function")));
 
+	/*
+	 * Deal with cases where both base and offset are infinite, and computing
+	 * base +/- offset would cause an error.  As for float and numeric types,
+	 * we assume that all values infinitely precede +infinity and infinitely
+	 * follow -infinity.  See in_range_float8_float8() for reasoning.
+	 */
+	if (INTERVAL_IS_NOEND(offset) &&
+		(sub ? INTERVAL_IS_NOEND(base) : INTERVAL_IS_NOBEGIN(base)))
+		PG_RETURN_BOOL(true);
+
 	/* We don't currently bother to avoid overflow hazards here */
 	if (sub)
 		sum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
@@ -3547,161 +3888,327 @@ in_range_interval_interval(PG_FUNCTION_ARGS)
 
 
 /*
- * interval_accum, interval_accum_inv, and interval_avg implement the
- * AVG(interval) aggregate.
+ * Prepare state data for an interval aggregate function, that needs to compute
+ * sum and count, in the aggregate's memory context.
  *
- * The transition datatype for this aggregate is a 2-element array of
- * intervals, where the first is the running sum and the second contains
- * the number of values so far in its 'time' field.  This is a bit ugly
- * but it beats inventing a specialized datatype for the purpose.
+ * The function is used when the state data needs to be allocated in aggregate's
+ * context. When the state data needs to be allocated in the current memory
+ * context, we use palloc0 directly e.g. interval_avg_deserialize().
+ */
+static IntervalAggState *
+makeIntervalAggState(FunctionCallInfo fcinfo)
+{
+	IntervalAggState *state;
+	MemoryContext agg_context;
+	MemoryContext old_context;
+
+	if (!AggCheckCallContext(fcinfo, &agg_context))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	old_context = MemoryContextSwitchTo(agg_context);
+
+	state = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
+
+	MemoryContextSwitchTo(old_context);
+
+	return state;
+}
+
+/*
+ * Accumulate a new input value for interval aggregate functions.
+ */
+static void
+do_interval_accum(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount++;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount++;
+		return;
+	}
+
+	finite_interval_pl(&state->sumX, newval, &state->sumX);
+	state->N++;
+}
+
+/*
+ * Remove the given interval value from the aggregated state.
+ */
+static void
+do_interval_discard(IntervalAggState *state, Interval *newval)
+{
+	/* Infinite inputs are counted separately, and do not affect "N" */
+	if (INTERVAL_IS_NOBEGIN(newval))
+	{
+		state->nInfcount--;
+		return;
+	}
+
+	if (INTERVAL_IS_NOEND(newval))
+	{
+		state->pInfcount--;
+		return;
+	}
+
+	/* Handle the to-be-discarded finite value. */
+	state->N--;
+	if (state->N > 0)
+		finite_interval_mi(&state->sumX, newval, &state->sumX);
+	else
+	{
+		/* All values discarded, reset the state */
+		Assert(state->N == 0);
+		memset(&state->sumX, 0, sizeof(state->sumX));
+	}
+}
+
+/*
+ * Transition function for sum() and avg() interval aggregates.
  */
+Datum
+interval_avg_accum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* Create the state data on the first call */
+	if (state == NULL)
+		state = makeIntervalAggState(fcinfo);
 
+	if (!PG_ARGISNULL(1))
+		do_interval_accum(state, PG_GETARG_INTERVAL_P(1));
+
+	PG_RETURN_POINTER(state);
+}
+
+/*
+ * Combine function for sum() and avg() interval aggregates.
+ *
+ * Combine the given internal aggregate states and place the combination in
+ * the first argument.
+ */
 Datum
-interval_accum(PG_FUNCTION_ARGS)
+interval_avg_combine(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	IntervalAggState *state1;
+	IntervalAggState *state2;
+
+	state1 = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+	state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	if (state2 == NULL)
+		PG_RETURN_POINTER(state1);
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	if (state1 == NULL)
+	{
+		/* manually copy all fields from state2 to state1 */
+		state1 = makeIntervalAggState(fcinfo);
+
+		state1->N = state2->N;
+		state1->pInfcount = state2->pInfcount;
+		state1->nInfcount = state2->nInfcount;
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time += 1;
+		state1->sumX.day = state2->sumX.day;
+		state1->sumX.month = state2->sumX.month;
+		state1->sumX.time = state2->sumX.time;
+
+		PG_RETURN_POINTER(state1);
+	}
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	state1->N += state2->N;
+	state1->pInfcount += state2->pInfcount;
+	state1->nInfcount += state2->nInfcount;
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* Accumulate finite interval values, if any. */
+	if (state2->N > 0)
+		finite_interval_pl(&state1->sumX, &state2->sumX, &state1->sumX);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_POINTER(state1);
 }
 
+/*
+ * interval_avg_serialize
+ *		Serialize IntervalAggState for interval aggregates.
+ */
 Datum
-interval_combine(PG_FUNCTION_ARGS)
+interval_avg_serialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray1 = PG_GETARG_ARRAYTYPE_P(0);
-	ArrayType  *transarray2 = PG_GETARG_ARRAYTYPE_P(1);
-	Datum	   *transdatums1;
-	Datum	   *transdatums2;
-	int			ndatums1;
-	int			ndatums2;
-	Interval	sum1,
-				N1;
-	Interval	sum2,
-				N2;
+	IntervalAggState *state;
+	StringInfoData buf;
+	bytea	   *result;
 
-	Interval   *newsum;
-	ArrayType  *result;
+	/* Ensure we disallow calling when not in aggregate context */
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
 
-	deconstruct_array(transarray1,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums1, NULL, &ndatums1);
-	if (ndatums1 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	state = (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	sum1 = *(DatumGetIntervalP(transdatums1[0]));
-	N1 = *(DatumGetIntervalP(transdatums1[1]));
+	pq_begintypsend(&buf);
 
-	deconstruct_array(transarray2,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums2, NULL, &ndatums2);
-	if (ndatums2 != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* N */
+	pq_sendint64(&buf, state->N);
 
-	sum2 = *(DatumGetIntervalP(transdatums2[0]));
-	N2 = *(DatumGetIntervalP(transdatums2[1]));
+	/* sumX */
+	pq_sendint64(&buf, state->sumX.time);
+	pq_sendint32(&buf, state->sumX.day);
+	pq_sendint32(&buf, state->sumX.month);
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_pl,
-												   IntervalPGetDatum(&sum1),
-												   IntervalPGetDatum(&sum2)));
-	N1.time += N2.time;
+	/* pInfcount */
+	pq_sendint64(&buf, state->pInfcount);
 
-	transdatums1[0] = IntervalPGetDatum(newsum);
-	transdatums1[1] = IntervalPGetDatum(&N1);
+	/* nInfcount */
+	pq_sendint64(&buf, state->nInfcount);
 
-	result = construct_array(transdatums1, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	result = pq_endtypsend(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	PG_RETURN_BYTEA_P(result);
 }
 
+/*
+ * interval_avg_deserialize
+ *		Deserialize bytea into IntervalAggState for interval aggregates.
+ */
 Datum
-interval_accum_inv(PG_FUNCTION_ARGS)
+interval_avg_deserialize(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Interval   *newval = PG_GETARG_INTERVAL_P(1);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
-	Interval   *newsum;
-	ArrayType  *result;
+	bytea	   *sstate;
+	IntervalAggState *result;
+	StringInfoData buf;
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	if (!AggCheckCallContext(fcinfo, NULL))
+		elog(ERROR, "aggregate function called in non-aggregate context");
+
+	sstate = PG_GETARG_BYTEA_PP(0);
+
+	/*
+	 * Initialize a StringInfo so that we can "receive" it using the standard
+	 * recv-function infrastructure.
+	 */
+	initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
+						   VARSIZE_ANY_EXHDR(sstate));
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	result = (IntervalAggState *) palloc0(sizeof(IntervalAggState));
 
-	newsum = DatumGetIntervalP(DirectFunctionCall2(interval_mi,
-												   IntervalPGetDatum(&sumX),
-												   IntervalPGetDatum(newval)));
-	N.time -= 1;
+	/* N */
+	result->N = pq_getmsgint64(&buf);
 
-	transdatums[0] = IntervalPGetDatum(newsum);
-	transdatums[1] = IntervalPGetDatum(&N);
+	/* sumX */
+	result->sumX.time = pq_getmsgint64(&buf);
+	result->sumX.day = pq_getmsgint(&buf, 4);
+	result->sumX.month = pq_getmsgint(&buf, 4);
 
-	result = construct_array(transdatums, 2,
-							 INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE);
+	/* pInfcount */
+	result->pInfcount = pq_getmsgint64(&buf);
 
-	PG_RETURN_ARRAYTYPE_P(result);
+	/* nInfcount */
+	result->nInfcount = pq_getmsgint64(&buf);
+
+	pq_getmsgend(&buf);
+
+	PG_RETURN_POINTER(result);
 }
 
+/*
+ * Inverse transition function for sum() and avg() interval aggregates.
+ */
 Datum
-interval_avg(PG_FUNCTION_ARGS)
+interval_avg_accum_inv(PG_FUNCTION_ARGS)
 {
-	ArrayType  *transarray = PG_GETARG_ARRAYTYPE_P(0);
-	Datum	   *transdatums;
-	int			ndatums;
-	Interval	sumX,
-				N;
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
 
-	deconstruct_array(transarray,
-					  INTERVALOID, sizeof(Interval), false, TYPALIGN_DOUBLE,
-					  &transdatums, NULL, &ndatums);
-	if (ndatums != 2)
-		elog(ERROR, "expected 2-element interval array");
+	/* Should not get here with no state */
+	if (state == NULL)
+		elog(ERROR, "interval_avg_accum_inv called with NULL state");
 
-	sumX = *(DatumGetIntervalP(transdatums[0]));
-	N = *(DatumGetIntervalP(transdatums[1]));
+	if (!PG_ARGISNULL(1))
+		do_interval_discard(state, PG_GETARG_INTERVAL_P(1));
 
-	/* SQL defines AVG of no values to be NULL */
-	if (N.time == 0)
+	PG_RETURN_POINTER(state);
+}
+
+/* avg(interval) aggregate final function */
+Datum
+interval_avg(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
 		PG_RETURN_NULL();
 
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 || state->nInfcount > 0)
+	{
+		Interval   *result;
+
+		if (state->pInfcount > 0 && state->nInfcount > 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range.")));
+
+		result = (Interval *) palloc(sizeof(Interval));
+		if (state->pInfcount > 0)
+			INTERVAL_NOEND(result);
+		else
+			INTERVAL_NOBEGIN(result);
+
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	return DirectFunctionCall2(interval_div,
-							   IntervalPGetDatum(&sumX),
-							   Float8GetDatum((double) N.time));
+							   IntervalPGetDatum(&state->sumX),
+							   Float8GetDatum((double) state->N));
 }
 
+/* sum(interval) aggregate final function */
+Datum
+interval_sum(PG_FUNCTION_ARGS)
+{
+	IntervalAggState *state;
+	Interval   *result;
+
+	state = PG_ARGISNULL(0) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(0);
+
+	/* If there were no non-null inputs, return NULL */
+	if (state == NULL || IA_TOTAL_COUNT(state) == 0)
+		PG_RETURN_NULL();
+
+	/*
+	 * Aggregating infinities that all have the same sign produces infinity
+	 * with that sign.  Aggregating infinities with different signs results in
+	 * an error.
+	 */
+	if (state->pInfcount > 0 && state->nInfcount > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("interval out of range.")));
+
+	result = (Interval *) palloc(sizeof(Interval));
+
+	if (state->pInfcount > 0)
+		INTERVAL_NOEND(result);
+	else if (state->nInfcount > 0)
+		INTERVAL_NOBEGIN(result);
+	else
+		memcpy(result, &state->sumX, sizeof(Interval));
+
+	PG_RETURN_INTERVAL_P(result);
+}
 
 /* timestamp_age()
  * Calculate time difference while retaining year/month fields.
@@ -3726,8 +4233,36 @@ timestamp_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, NULL, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, NULL, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3846,8 +4381,36 @@ timestamptz_age(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
-	if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
-		timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
+	/*
+	 * Handle infinities.
+	 *
+	 * We treat anything that amounts to "infinity - infinity" as an error,
+	 * since the interval type has nothing equivalent to NaN.
+	 */
+	if (TIMESTAMP_IS_NOBEGIN(dt1))
+	{
+		if (TIMESTAMP_IS_NOBEGIN(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOBEGIN(result);
+	}
+	else if (TIMESTAMP_IS_NOEND(dt1))
+	{
+		if (TIMESTAMP_IS_NOEND(dt2))
+			ereport(ERROR,
+					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+					 errmsg("interval out of range")));
+		else
+			INTERVAL_NOEND(result);
+	}
+	else if (TIMESTAMP_IS_NOBEGIN(dt2))
+		INTERVAL_NOEND(result);
+	else if (TIMESTAMP_IS_NOEND(dt2))
+		INTERVAL_NOBEGIN(result);
+	else if (timestamp2tm(dt1, &tz1, tm1, &fsec1, NULL, NULL) == 0 &&
+			 timestamp2tm(dt2, &tz2, tm2, &fsec2, NULL, NULL) == 0)
 	{
 		/* form the symbolic difference */
 		tm->tm_usec = fsec1 - fsec2;
@@ -3972,6 +4535,11 @@ timestamp_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4155,6 +4723,11 @@ timestamptz_bin(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("origin out of range")));
 
+	if (INTERVAL_NOT_FINITE(stride))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("timestamps cannot be binned into infinite intervals")));
+
 	if (stride->month != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4393,6 +4966,12 @@ interval_trunc(PG_FUNCTION_ARGS)
 
 	result = (Interval *) palloc(sizeof(Interval));
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		memcpy(result, interval, sizeof(Interval));
+		PG_RETURN_INTERVAL_P(result);
+	}
+
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -4737,7 +5316,7 @@ timestamp_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 false);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5011,7 +5590,7 @@ timestamptz_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 												 TIMESTAMP_IS_NOBEGIN(timestamp),
 												 true);
 
-		if (r)
+		if (r != 0.0)
 		{
 			if (retnumeric)
 			{
@@ -5251,6 +5830,58 @@ extract_timestamptz(PG_FUNCTION_ARGS)
 	return timestamptz_part_common(fcinfo, true);
 }
 
+/*
+ * NonFiniteIntervalPart
+ *
+ *	Used by interval_part when extracting from infinite interval.  Returns
+ *	+/-Infinity if that is the appropriate result, otherwise returns zero
+ *	(which should be taken as meaning to return NULL).
+ *
+ *	Errors thrown here for invalid units should exactly match those that
+ *	would be thrown in the calling functions, else there will be unexpected
+ *	discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteIntervalPart(int type, int unit, char *lowunits, bool isNegative)
+{
+	if ((type != UNITS) && (type != RESERV))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("unit \"%s\" not recognized for type %s",
+						lowunits, format_type_be(INTERVALOID))));
+
+	switch (unit)
+	{
+			/* Oscillating units */
+		case DTK_MICROSEC:
+		case DTK_MILLISEC:
+		case DTK_SECOND:
+		case DTK_MINUTE:
+		case DTK_MONTH:
+		case DTK_QUARTER:
+			return 0.0;
+
+			/* Monotonically-increasing units */
+		case DTK_HOUR:
+		case DTK_DAY:
+		case DTK_YEAR:
+		case DTK_DECADE:
+		case DTK_CENTURY:
+		case DTK_MILLENNIUM:
+		case DTK_EPOCH:
+			if (isNegative)
+				return -get_float8_infinity();
+			else
+				return get_float8_infinity();
+
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("unit \"%s\" not supported for type %s",
+							lowunits, format_type_be(INTERVALOID))));
+			return 0.0;			/* keep compiler quiet */
+	}
+}
 
 /* interval_part() and extract_interval()
  * Extract specified field from interval.
@@ -5275,6 +5906,33 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric)
 	if (type == UNKNOWN_FIELD)
 		type = DecodeSpecial(0, lowunits, &val);
 
+	if (INTERVAL_NOT_FINITE(interval))
+	{
+		double		r = NonFiniteIntervalPart(type, val, lowunits,
+											  INTERVAL_IS_NOBEGIN(interval));
+
+		if (r != 0.0)
+		{
+			if (retnumeric)
+			{
+				if (r < 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("-Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+				else if (r > 0)
+					return DirectFunctionCall3(numeric_in,
+											   CStringGetDatum("Infinity"),
+											   ObjectIdGetDatum(InvalidOid),
+											   Int32GetDatum(-1));
+			}
+			else
+				PG_RETURN_FLOAT8(r);
+		}
+		else
+			PG_RETURN_NULL();
+	}
+
 	if (type == UNITS)
 	{
 		interval2itm(*interval, tm);
@@ -5517,6 +6175,13 @@ timestamp_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMPTZ(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5747,6 +6412,13 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(timestamp))
 		PG_RETURN_TIMESTAMP(timestamp);
 
+	if (INTERVAL_NOT_FINITE(zone))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("interval time zone \"%s\" must be finite",
+						DatumGetCString(DirectFunctionCall1(interval_out,
+															PointerGetDatum(zone))))));
+
 	if (zone->month != 0 || zone->day != 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -5783,7 +6455,6 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		Timestamp	finish = PG_GETARG_TIMESTAMP(1);
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5806,13 +6477,18 @@ generate_series_timestamp(PG_FUNCTION_ARGS)
 		fctx->step = *step;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
@@ -5864,7 +6540,6 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		Interval   *step = PG_GETARG_INTERVAL_P(2);
 		text	   *zone = (PG_NARGS() == 4) ? PG_GETARG_TEXT_PP(3) : NULL;
 		MemoryContext oldcontext;
-		const Interval interval_zero = {0};
 
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
@@ -5888,13 +6563,18 @@ generate_series_timestamptz_internal(FunctionCallInfo fcinfo)
 		fctx->attimezone = zone ? lookup_timezone(zone) : session_timezone;
 
 		/* Determine sign of the interval */
-		fctx->step_sign = interval_cmp_internal(&fctx->step, &interval_zero);
+		fctx->step_sign = interval_sign(&fctx->step);
 
 		if (fctx->step_sign == 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 					 errmsg("step size cannot equal zero")));
 
+		if (INTERVAL_NOT_FINITE((&fctx->step)))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("step size cannot be infinite")));
+
 		funcctx->user_fctx = fctx;
 		MemoryContextSwitchTo(oldcontext);
 	}
diff --git a/src/include/catalog/pg_aggregate.dat b/src/include/catalog/pg_aggregate.dat
index 1bc1d97d74..e1a17cddd8 100644
--- a/src/include/catalog/pg_aggregate.dat
+++ b/src/include/catalog/pg_aggregate.dat
@@ -43,12 +43,13 @@
 { aggfnoid => 'avg(float8)', aggtransfn => 'float8_accum',
   aggfinalfn => 'float8_avg', aggcombinefn => 'float8_combine',
   aggtranstype => '_float8', agginitval => '{0,0,0}' },
-{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_accum',
-  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_combine',
-  aggmtransfn => 'interval_accum', aggminvtransfn => 'interval_accum_inv',
-  aggmfinalfn => 'interval_avg', aggtranstype => '_interval',
-  aggmtranstype => '_interval', agginitval => '{0 second,0 second}',
-  aggminitval => '{0 second,0 second}' },
+{ aggfnoid => 'avg(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_avg', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_avg', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40' },
 
 # sum
 { aggfnoid => 'sum(int8)', aggtransfn => 'int8_avg_accum',
@@ -72,10 +73,13 @@
 { aggfnoid => 'sum(money)', aggtransfn => 'cash_pl', aggcombinefn => 'cash_pl',
   aggmtransfn => 'cash_pl', aggminvtransfn => 'cash_mi',
   aggtranstype => 'money', aggmtranstype => 'money' },
-{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_pl',
-  aggcombinefn => 'interval_pl', aggmtransfn => 'interval_pl',
-  aggminvtransfn => 'interval_mi', aggtranstype => 'interval',
-  aggmtranstype => 'interval' },
+{ aggfnoid => 'sum(interval)', aggtransfn => 'interval_avg_accum',
+  aggfinalfn => 'interval_sum', aggcombinefn => 'interval_avg_combine',
+  aggserialfn => 'interval_avg_serialize',
+  aggdeserialfn => 'interval_avg_deserialize',
+  aggmtransfn => 'interval_avg_accum', aggminvtransfn => 'interval_avg_accum_inv',
+  aggmfinalfn => 'interval_sum', aggtranstype => 'internal',
+  aggtransspace => '40', aggmtranstype => 'internal', aggmtransspace => '40'},
 { aggfnoid => 'sum(numeric)', aggtransfn => 'numeric_avg_accum',
   aggfinalfn => 'numeric_sum', aggcombinefn => 'numeric_avg_combine',
   aggserialfn => 'numeric_avg_serialize',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f14aed422a..d6a990e531 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4917,17 +4917,29 @@
   prosrc => 'numeric_poly_stddev_samp' },
 
 { oid => '1843', descr => 'aggregate transition function',
-  proname => 'interval_accum', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum' },
+  proname => 'interval_avg_accum', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum' },
 { oid => '3325', descr => 'aggregate combine function',
-  proname => 'interval_combine', prorettype => '_interval',
-  proargtypes => '_interval _interval', prosrc => 'interval_combine' },
+  proname => 'interval_avg_combine', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal internal',
+  prosrc => 'interval_avg_combine' },
 { oid => '3549', descr => 'aggregate transition function',
-  proname => 'interval_accum_inv', prorettype => '_interval',
-  proargtypes => '_interval interval', prosrc => 'interval_accum_inv' },
+  proname => 'interval_avg_accum_inv', proisstrict => 'f',
+  prorettype => 'internal', proargtypes => 'internal interval',
+  prosrc => 'interval_avg_accum_inv' },
+{ oid => '8505', descr => 'aggregate serial function',
+  proname => 'interval_avg_serialize', prorettype => 'bytea',
+  proargtypes => 'internal', prosrc => 'interval_avg_serialize' },
+{ oid => '8506', descr => 'aggregate deserial function',
+  proname => 'interval_avg_deserialize', prorettype => 'internal',
+  proargtypes => 'bytea internal', prosrc => 'interval_avg_deserialize' },
 { oid => '1844', descr => 'aggregate final function',
-  proname => 'interval_avg', prorettype => 'interval',
-  proargtypes => '_interval', prosrc => 'interval_avg' },
+  proname => 'interval_avg', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_avg' },
+{ oid => '8507', descr => 'aggregate final function',
+  proname => 'interval_sum', proisstrict => 'f', prorettype => 'interval',
+  proargtypes => 'internal', prosrc => 'interval_sum' },
 { oid => '1962', descr => 'aggregate transition function',
   proname => 'int2_avg_accum', prorettype => '_int8',
   proargtypes => '_int8 int2', prosrc => 'int2_avg_accum' },
diff --git a/src/include/datatype/timestamp.h b/src/include/datatype/timestamp.h
index 1a6390585c..b63acc0a2f 100644
--- a/src/include/datatype/timestamp.h
+++ b/src/include/datatype/timestamp.h
@@ -151,7 +151,7 @@ struct pg_itm_in
 #define TIMESTAMP_INFINITY	PG_INT64_MAX
 
 /*
- * Historically these alias for infinity have been used.
+ * Historically these aliases for infinity have been used.
  */
 #define DT_NOBEGIN		TIMESTAMP_MINUS_INFINITY
 #define DT_NOEND		TIMESTAMP_INFINITY
@@ -168,6 +168,31 @@ struct pg_itm_in
 
 #define TIMESTAMP_NOT_FINITE(j) (TIMESTAMP_IS_NOBEGIN(j) || TIMESTAMP_IS_NOEND(j))
 
+/*
+ * Infinite intervals are represented by setting all fields to the minimum or
+ * maximum integer values.
+ */
+#define INTERVAL_NOBEGIN(i)	\
+	do {	\
+		(i)->time = PG_INT64_MIN;	\
+		(i)->day = PG_INT32_MIN;	\
+		(i)->month = PG_INT32_MIN;	\
+	} while (0)
+
+#define INTERVAL_IS_NOBEGIN(i)	\
+	((i)->month == PG_INT32_MIN && (i)->day == PG_INT32_MIN && (i)->time == PG_INT64_MIN)
+
+#define INTERVAL_NOEND(i)	\
+	do {	\
+		(i)->time = PG_INT64_MAX;	\
+		(i)->day = PG_INT32_MAX;	\
+		(i)->month = PG_INT32_MAX;	\
+	} while (0)
+
+#define INTERVAL_IS_NOEND(i)	\
+	((i)->month == PG_INT32_MAX && (i)->day == PG_INT32_MAX && (i)->time == PG_INT64_MAX)
+
+#define INTERVAL_NOT_FINITE(i) (INTERVAL_IS_NOBEGIN(i) || INTERVAL_IS_NOEND(i))
 
 /*
  * Julian date support.
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 80801cd4ee..8f4c95b9e6 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -941,6 +941,34 @@ SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
          Index Cond: (a = '@ 30 years'::interval)
 (4 rows)
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+SET enable_seqscan = off;
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years ago'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years ago'::interval)
+(4 rows)
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+                                 QUERY PLAN                                  
+-----------------------------------------------------------------------------
+ Bitmap Heap Scan on brin_interval_test (actual rows=0 loops=1)
+   Recheck Cond: (a = '@ 30 years'::interval)
+   ->  Bitmap Index Scan on brin_interval_test_a_idx (actual rows=0 loops=1)
+         Index Cond: (a = '@ 30 years'::interval)
+(4 rows)
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out
index 8f52661096..cfb4b205e4 100644
--- a/src/test/regress/expected/horology.out
+++ b/src/test/regress/expected/horology.out
@@ -1171,6 +1171,7 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
       t      |               i               |     add     |  subtract   
 -------------+-------------------------------+-------------+-------------
@@ -1278,6 +1279,7 @@ SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
        t        |               i               |      add       |    subtract    
 ----------------+-------------------------------+----------------+----------------
@@ -1556,6 +1558,22 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
   ORDER BY plus, "timestamp", "interval";
           timestamp           |           interval            |             plus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | -infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | -infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | -infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | -infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | -infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | -infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | -infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | -infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | -infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 14 secs ago                 | Wed Dec 31 23:59:46 1969 PST
  Thu Jan 01 00:00:00 1970 PST | @ 1 min                       | Thu Jan 01 00:01:00 1970 PST
  Thu Jan 01 00:00:00 1970 PST | @ 5 hours                     | Thu Jan 01 05:00:00 1970 PST
@@ -1716,14 +1734,45 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
  Sun Dec 31 17:32:01 2000 PST | @ 34 years                    | Sun Dec 31 17:32:01 2034 PST
  Mon Jan 01 17:32:01 2001 PST | @ 34 years                    | Mon Jan 01 17:32:01 2035 PST
  Sat Sep 22 18:19:20 2001 PDT | @ 34 years                    | Sat Sep 22 18:19:20 2035 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
           timestamp           |           interval            |            minus             
 ------------------------------+-------------------------------+------------------------------
+ Thu Jan 01 00:00:00 1970 PST | infinity                      | -infinity
+ Wed Feb 28 17:32:01 1996 PST | infinity                      | -infinity
+ Thu Feb 29 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Mar 01 17:32:01 1996 PST | infinity                      | -infinity
+ Mon Dec 30 17:32:01 1996 PST | infinity                      | -infinity
+ Tue Dec 31 17:32:01 1996 PST | infinity                      | -infinity
+ Fri Dec 31 17:32:01 1999 PST | infinity                      | -infinity
+ Sat Jan 01 17:32:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 02:14:05 2000 PST | infinity                      | -infinity
+ Wed Mar 15 03:14:04 2000 PST | infinity                      | -infinity
+ Wed Mar 15 08:14:01 2000 PST | infinity                      | -infinity
+ Wed Mar 15 12:14:03 2000 PST | infinity                      | -infinity
+ Wed Mar 15 13:14:02 2000 PST | infinity                      | -infinity
+ Sun Dec 31 17:32:01 2000 PST | infinity                      | -infinity
+ Mon Jan 01 17:32:01 2001 PST | infinity                      | -infinity
+ Sat Sep 22 18:19:20 2001 PDT | infinity                      | -infinity
  Thu Jan 01 00:00:00 1970 PST | @ 34 years                    | Wed Jan 01 00:00:00 1936 PST
  Wed Feb 28 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
  Thu Feb 29 17:32:01 1996 PST | @ 34 years                    | Wed Feb 28 17:32:01 1962 PST
@@ -1884,7 +1933,23 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
  Sat Sep 22 18:19:20 2001 PDT | @ 5 hours                     | Sat Sep 22 13:19:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 1 min                       | Sat Sep 22 18:18:20 2001 PDT
  Sat Sep 22 18:19:20 2001 PDT | @ 14 secs ago                 | Sat Sep 22 18:19:34 2001 PDT
-(160 rows)
+ Thu Jan 01 00:00:00 1970 PST | -infinity                     | infinity
+ Wed Feb 28 17:32:01 1996 PST | -infinity                     | infinity
+ Thu Feb 29 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Mar 01 17:32:01 1996 PST | -infinity                     | infinity
+ Mon Dec 30 17:32:01 1996 PST | -infinity                     | infinity
+ Tue Dec 31 17:32:01 1996 PST | -infinity                     | infinity
+ Fri Dec 31 17:32:01 1999 PST | -infinity                     | infinity
+ Sat Jan 01 17:32:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 02:14:05 2000 PST | -infinity                     | infinity
+ Wed Mar 15 03:14:04 2000 PST | -infinity                     | infinity
+ Wed Mar 15 08:14:01 2000 PST | -infinity                     | infinity
+ Wed Mar 15 12:14:03 2000 PST | -infinity                     | infinity
+ Wed Mar 15 13:14:02 2000 PST | -infinity                     | infinity
+ Sun Dec 31 17:32:01 2000 PST | -infinity                     | infinity
+ Mon Jan 01 17:32:01 2001 PST | -infinity                     | infinity
+ Sat Sep 22 18:19:20 2001 PDT | -infinity                     | infinity
+(192 rows)
 
 SELECT d.f1 AS "timestamp",
    timestamp with time zone '1980-01-06 00:00 GMT' AS gpstime_zero,
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 75d19d6594..a481781475 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -52,6 +52,18 @@ SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
  9 years 1 mon -12 days +13:14:00
 (1 row)
 
+SELECT INTERVAL 'infinity' AS "eternity";
+ eternity 
+----------
+ infinity
+(1 row)
+
+SELECT INTERVAL '-infinity' AS "beginning of time";
+ beginning of time 
+-------------------
+ -infinity
+(1 row)
+
 CREATE TABLE INTERVAL_TBL (f1 interval);
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 1 minute');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('@ 5 hour');
@@ -63,6 +75,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
 ERROR:  invalid input syntax for type interval: "badly formatted interval"
@@ -117,7 +131,9 @@ SELECT * FROM INTERVAL_TBL;
  6 years
  5 mons
  5 mons 12:00:00
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <> interval '@ 10 days';
@@ -132,7 +148,9 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+ -infinity
+(11 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 <= interval '@ 5 hours';
@@ -141,7 +159,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 < interval '@ 1 day';
@@ -150,7 +169,8 @@ SELECT * FROM INTERVAL_TBL
  00:01:00
  05:00:00
  -00:00:14
-(3 rows)
+ -infinity
+(4 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 = interval '@ 34 years';
@@ -168,7 +188,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(5 rows)
+ infinity
+(6 rows)
 
 SELECT * FROM INTERVAL_TBL
    WHERE INTERVAL_TBL.f1 > interval '@ 3 seconds ago';
@@ -183,7 +204,8 @@ SELECT * FROM INTERVAL_TBL
  6 years
  5 mons
  5 mons 12:00:00
-(9 rows)
+ infinity
+(10 rows)
 
 SELECT r1.*, r2.*
    FROM INTERVAL_TBL r1, INTERVAL_TBL r2
@@ -191,27 +213,35 @@ SELECT r1.*, r2.*
    ORDER BY r1.f1, r2.f1;
        f1        |       f1        
 -----------------+-----------------
+ -00:00:14       | -infinity
+ 00:01:00        | -infinity
  00:01:00        | -00:00:14
+ 05:00:00        | -infinity
  05:00:00        | -00:00:14
  05:00:00        | 00:01:00
+ 1 day 02:03:04  | -infinity
  1 day 02:03:04  | -00:00:14
  1 day 02:03:04  | 00:01:00
  1 day 02:03:04  | 05:00:00
+ 10 days         | -infinity
  10 days         | -00:00:14
  10 days         | 00:01:00
  10 days         | 05:00:00
  10 days         | 1 day 02:03:04
+ 3 mons          | -infinity
  3 mons          | -00:00:14
  3 mons          | 00:01:00
  3 mons          | 05:00:00
  3 mons          | 1 day 02:03:04
  3 mons          | 10 days
+ 5 mons          | -infinity
  5 mons          | -00:00:14
  5 mons          | 00:01:00
  5 mons          | 05:00:00
  5 mons          | 1 day 02:03:04
  5 mons          | 10 days
  5 mons          | 3 mons
+ 5 mons 12:00:00 | -infinity
  5 mons 12:00:00 | -00:00:14
  5 mons 12:00:00 | 00:01:00
  5 mons 12:00:00 | 05:00:00
@@ -219,6 +249,7 @@ SELECT r1.*, r2.*
  5 mons 12:00:00 | 10 days
  5 mons 12:00:00 | 3 mons
  5 mons 12:00:00 | 5 mons
+ 6 years         | -infinity
  6 years         | -00:00:14
  6 years         | 00:01:00
  6 years         | 05:00:00
@@ -227,6 +258,7 @@ SELECT r1.*, r2.*
  6 years         | 3 mons
  6 years         | 5 mons
  6 years         | 5 mons 12:00:00
+ 34 years        | -infinity
  34 years        | -00:00:14
  34 years        | 00:01:00
  34 years        | 05:00:00
@@ -236,8 +268,63 @@ SELECT r1.*, r2.*
  34 years        | 5 mons
  34 years        | 5 mons 12:00:00
  34 years        | 6 years
-(45 rows)
+ infinity        | -infinity
+ infinity        | -00:00:14
+ infinity        | 00:01:00
+ infinity        | 05:00:00
+ infinity        | 1 day 02:03:04
+ infinity        | 10 days
+ infinity        | 3 mons
+ infinity        | 5 mons
+ infinity        | 5 mons 12:00:00
+ infinity        | 6 years
+ infinity        | 34 years
+(66 rows)
+
+-- test unary minus
+SELECT f1, -f1 FROM INTERVAL_TBL;
+       f1        |     ?column?      
+-----------------+-------------------
+ 00:01:00        | -00:01:00
+ 05:00:00        | -05:00:00
+ 10 days         | -10 days
+ 34 years        | -34 years
+ 3 mons          | -3 mons
+ -00:00:14       | 00:00:14
+ 1 day 02:03:04  | -1 days -02:03:04
+ 6 years         | -6 years
+ 5 mons          | -5 mons
+ 5 mons 12:00:00 | -5 mons -12:00:00
+ infinity        | -infinity
+ -infinity       | infinity
+(12 rows)
+
+SELECT -('-2147483648 months'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 months'::interval); -- ok
+        ?column?        
+------------------------
+ 178956970 years 7 mons
+(1 row)
+
+SELECT -('-2147483648 days'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-2147483647 days'::interval); -- ok
+    ?column?     
+-----------------
+ 2147483647 days
+(1 row)
+
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+ERROR:  interval out of range
+SELECT -('-9223372036854775807 us'::interval); -- ok
+        ?column?         
+-------------------------
+ 2562047788:00:54.775807
+(1 row)
 
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+ERROR:  interval out of range
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -304,6 +391,17 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 (5 rows)
 
 RESET enable_seqscan;
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+ ?column? 
+----------
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+ 00:00:00
+(5 rows)
+
 DROP TABLE INTERVAL_TBL_OF;
 -- Test multiplication and division with intervals.
 -- Floating point arithmetic rounding errors can lead to unexpected results,
@@ -386,12 +484,14 @@ SELECT * FROM INTERVAL_TBL;
  @ 6 years
  @ 5 mons
  @ 5 mons 12 hours
-(10 rows)
+ infinity
+ -infinity
+(12 rows)
 
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
                        avg                       
 -------------------------------------------------
  @ 4 years 1 mon 10 days 4 hours 18 mins 23 secs
@@ -820,8 +920,8 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
 SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
   (f1 + INTERVAL '1 month')::INTERVAL MONTH::INTERVAL YEAR AS "years"
   FROM interval_tbl;
-       f1        |     minutes     |  years   
------------------+-----------------+----------
+       f1        |     minutes     |   years   
+-----------------+-----------------+-----------
  00:01:00        | 00:01:00        | 00:00:00
  05:00:00        | 05:00:00        | 00:00:00
  10 days         | 10 days         | 00:00:00
@@ -832,7 +932,9 @@ SELECT f1, f1::INTERVAL DAY TO MINUTE AS "minutes",
  6 years         | 6 years         | 6 years
  5 mons          | 5 mons          | 00:00:00
  5 mons 12:00:00 | 5 mons 12:00:00 | 00:00:00
-(10 rows)
+ infinity        | infinity        | infinity
+ -infinity       | -infinity       | -infinity
+(12 rows)
 
 -- test inputting and outputting SQL standard interval literals
 SET IntervalStyle TO sql_standard;
@@ -1616,31 +1718,31 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 ERROR:  interval out of range
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                               interval                              
 --------------------------------------------------------------------
- -178956970 years -8 mons -2147483648 days -2562047788:00:54.775808
+ -178956970 years -7 mons -2147483648 days -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                      interval                      
 ---------------------------------------------------
- -178956970-8 -2147483648 -2562047788:00:54.775808
+ -178956970-7 -2147483648 -2562047788:00:54.775808
 (1 row)
 
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                       interval                       
 -----------------------------------------------------
- P-178956970Y-8M-2147483648DT-2562047788H-54.775808S
+ P-178956970Y-7M-2147483648DT-2562047788H-54.775808S
 (1 row)
 
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
                                    interval                                   
 ------------------------------------------------------------------------------
- @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775808 secs ago
+ @ 178956970 years 7 mons 2147483648 days 2562047788 hours 54.775808 secs ago
 (1 row)
 
 -- check that '30 days' equals '1 month' according to the hash function
@@ -1719,19 +1821,21 @@ SELECT f1,
     EXTRACT(MILLENNIUM FROM f1) AS MILLENNIUM,
     EXTRACT(EPOCH FROM f1) AS EPOCH
     FROM INTERVAL_TBL;
-              f1               | microsecond | millisecond |   second   | minute | hour | day | month | quarter | year | decade | century | millennium |       epoch       
--------------------------------+-------------+-------------+------------+--------+------+-----+-------+---------+------+--------+---------+------------+-------------------
- @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |         60.000000
- @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |    5 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |      18000.000000
- @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |    0 |  10 |     0 |       1 |    0 |      0 |       0 |          0 |     864000.000000
- @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |   34 |      3 |       0 |          0 | 1072958400.000000
- @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     3 |       2 |    0 |      0 |       0 |          0 |    7776000.000000
- @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |    0 |   0 |     0 |       1 |    0 |      0 |       0 |          0 |        -14.000000
- @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |    2 |   1 |     0 |       1 |    0 |      0 |       0 |          0 |      93784.000000
- @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     0 |       1 |    6 |      0 |       0 |          0 |  189345600.000000
- @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |    0 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   12960000.000000
- @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |   12 |   0 |     5 |       2 |    0 |      0 |       0 |          0 |   13003200.000000
-(10 rows)
+              f1               | microsecond | millisecond |   second   | minute |   hour    |    day    | month | quarter |   year    |  decade   |  century  | millennium |       epoch       
+-------------------------------+-------------+-------------+------------+--------+-----------+-----------+-------+---------+-----------+-----------+-----------+------------+-------------------
+ @ 1 min                       |           0 |       0.000 |   0.000000 |      1 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |         60.000000
+ @ 5 hours                     |           0 |       0.000 |   0.000000 |      0 |         5 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |      18000.000000
+ @ 10 days                     |           0 |       0.000 |   0.000000 |      0 |         0 |        10 |     0 |       1 |         0 |         0 |         0 |          0 |     864000.000000
+ @ 34 years                    |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |        34 |         3 |         0 |          0 | 1072958400.000000
+ @ 3 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     3 |       2 |         0 |         0 |         0 |          0 |    7776000.000000
+ @ 14 secs ago                 |   -14000000 |  -14000.000 | -14.000000 |      0 |         0 |         0 |     0 |       1 |         0 |         0 |         0 |          0 |        -14.000000
+ @ 1 day 2 hours 3 mins 4 secs |     4000000 |    4000.000 |   4.000000 |      3 |         2 |         1 |     0 |       1 |         0 |         0 |         0 |          0 |      93784.000000
+ @ 6 years                     |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     0 |       1 |         6 |         0 |         0 |          0 |  189345600.000000
+ @ 5 mons                      |           0 |       0.000 |   0.000000 |      0 |         0 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   12960000.000000
+ @ 5 mons 12 hours             |           0 |       0.000 |   0.000000 |      0 |        12 |         0 |     5 |       2 |         0 |         0 |         0 |          0 |   13003200.000000
+ infinity                      |             |             |            |        |  Infinity |  Infinity |       |         |  Infinity |  Infinity |  Infinity |   Infinity |          Infinity
+ -infinity                     |             |             |            |        | -Infinity | -Infinity |       |         | -Infinity | -Infinity | -Infinity |  -Infinity |         -Infinity
+(12 rows)
 
 SELECT EXTRACT(FORTNIGHT FROM INTERVAL '2 days');  -- error
 ERROR:  unit "fortnight" not recognized for type interval
@@ -1805,7 +1909,9 @@ SELECT f1,
  @ 6 years                     |           0 |           0 |      0 |  189345600
  @ 5 mons                      |           0 |           0 |      0 |   12960000
  @ 5 mons 12 hours             |           0 |           0 |      0 |   13003200
-(10 rows)
+ infinity                      |             |             |        |   Infinity
+ -infinity                     |             |             |        |  -Infinity
+(12 rows)
 
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
@@ -1814,6 +1920,292 @@ SELECT extract(epoch from interval '1000000000 days');
  86400000000000.000000
 (1 row)
 
+--
+-- test infinite intervals
+--
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+                                   interval                                   
+------------------------------------------------------------------------------
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+                                 interval                                 
+--------------------------------------------------------------------------
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs
+(1 row)
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+ interval  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+ interval 
+----------
+ infinity
+(1 row)
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+            i            | isfinite 
+-------------------------+----------
+ infinity                | f
+ -infinity               | f
+ @ 1 year 2 days 3 hours | t
+(3 rows)
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+    date    | interval  |          plus          |         minus          
+------------+-----------+------------------------+------------------------
+ -infinity  | -infinity | -infinity              | timestamp out of range
+ -infinity  | infinity  | timestamp out of range | -infinity
+ 1995-08-06 | -infinity | -infinity              | infinity
+ 1995-08-06 | infinity  | infinity               | -infinity
+ infinity   | -infinity | timestamp out of range | infinity
+ infinity   | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+ interval1 | interval2 |         plus          |         minus         
+-----------+-----------+-----------------------+-----------------------
+ -infinity | -infinity | -infinity             | interval out of range
+ -infinity | @ 10 days | -infinity             | -infinity
+ -infinity | infinity  | interval out of range | -infinity
+ @ 2 mons  | -infinity | -infinity             | infinity
+ @ 2 mons  | @ 10 days | @ 2 mons 10 days      | @ 2 mons -10 days
+ @ 2 mons  | infinity  | infinity              | -infinity
+ infinity  | -infinity | interval out of range | infinity
+ infinity  | @ 10 days | infinity              | infinity
+ infinity  | infinity  | infinity              | interval out of range
+(9 rows)
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+ERROR:  interval out of range
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+ERROR:  interval out of range
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+      timestamp      | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+     timestamptz     | interval  |          plus          |         minus          
+---------------------+-----------+------------------------+------------------------
+ -infinity           | -infinity | -infinity              | timestamp out of range
+ -infinity           | infinity  | timestamp out of range | -infinity
+ 1995-08-06 12:30:15 | -infinity | -infinity              | infinity
+ 1995-08-06 12:30:15 | infinity  | infinity               | -infinity
+ infinity            | -infinity | timestamp out of range | infinity
+ infinity            | infinity  | infinity               | timestamp out of range
+(6 rows)
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT time '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT time '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' + interval 'infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' + interval '-infinity';
+ERROR:  cannot add infinite interval to time
+SELECT timetz '11:27:42' - interval 'infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT timetz '11:27:42' - interval '-infinity';
+ERROR:  cannot subtract infinite interval from time
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+    lhs    |           rhs           | lt | le | eq | gt | ge | ne 
+-----------+-------------------------+----+----+----+----+----+----
+ infinity  | infinity                | f  | t  | t  | f  | t  | f
+ -infinity | infinity                | t  | t  | f  | f  | f  | t
+ infinity  | -infinity               | f  | f  | f  | t  | t  | t
+ -infinity | -infinity               | f  | t  | t  | f  | t  | f
+ infinity  | @ 1 year 2 days 3 hours | f  | f  | f  | t  | t  | t
+ -infinity | @ 1 year 2 days 3 hours | t  | t  | f  | f  | f  | t
+(6 rows)
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  |    um     |    mul    |  mul_neg  |  mul_inf  | mul_inf_neg |    div    |  div_neg  
+-----------+-----------+-----------+-----------+-----------+-------------+-----------+-----------
+ infinity  | -infinity | infinity  | -infinity | infinity  | -infinity   | infinity  | -infinity
+ -infinity | infinity  | -infinity | infinity  | -infinity | infinity    | -infinity | infinity
+(2 rows)
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+ERROR:  interval out of range
+SELECT interval 'infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' * 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+ERROR:  interval out of range
+SELECT interval 'infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '-infinity' * 0;
+ERROR:  interval out of range
+SELECT interval '0 days' * 'infinity'::float;
+ERROR:  interval out of range
+SELECT interval '0 days' * '-infinity'::float;
+ERROR:  interval out of range
+SELECT interval '5 days' * 'infinity'::float;
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT interval '5 days' * '-infinity'::float;
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT interval 'infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval 'infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / '-infinity';
+ERROR:  interval out of range
+SELECT interval '-infinity' / 'nan';
+ERROR:  interval out of range
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+ERROR:  interval out of range
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+ERROR:  timestamps cannot be binned into infinite intervals
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | date_trunc 
+-----------+------------
+ infinity  | infinity
+ -infinity | -infinity
+(2 rows)
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ interval  | justify_days | justify_hours | justify_interval 
+-----------+--------------+---------------+------------------
+ infinity  | infinity     | infinity      | infinity
+ -infinity | -infinity    | -infinity     | -infinity
+(2 rows)
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "infinity" must be finite
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+ERROR:  interval time zone "-infinity" must be finite
+SELECT 'infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT '-infinity'::interval::time;
+ERROR:  cannot convert infinite interval to time
+SELECT to_char('infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
+SELECT to_char('-infinity'::interval, 'YYYY');
+ to_char 
+---------
+ 
+(1 row)
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 ERROR:  invalid input syntax for type interval: "42 days 2 seconds ago ago"
@@ -1832,3 +2224,42 @@ SELECT INTERVAL '1 year months days 5 hours';
 ERROR:  invalid input syntax for type interval: "1 year months days 5 hours"
 LINE 1: SELECT INTERVAL '1 year months days 5 hours';
                         ^
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+ERROR:  invalid input syntax for type interval: "now"
+LINE 1: SELECT INTERVAL 'now';
+                        ^
+SELECT INTERVAL 'today';
+ERROR:  invalid input syntax for type interval: "today"
+LINE 1: SELECT INTERVAL 'today';
+                        ^
+SELECT INTERVAL 'tomorrow';
+ERROR:  invalid input syntax for type interval: "tomorrow"
+LINE 1: SELECT INTERVAL 'tomorrow';
+                        ^
+SELECT INTERVAL 'allballs';
+ERROR:  invalid input syntax for type interval: "allballs"
+LINE 1: SELECT INTERVAL 'allballs';
+                        ^
+SELECT INTERVAL 'epoch';
+ERROR:  invalid input syntax for type interval: "epoch"
+LINE 1: SELECT INTERVAL 'epoch';
+                        ^
+SELECT INTERVAL 'yesterday';
+ERROR:  invalid input syntax for type interval: "yesterday"
+LINE 1: SELECT INTERVAL 'yesterday';
+                        ^
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+ERROR:  invalid input syntax for type interval: "infinity years"
+LINE 1: SELECT INTERVAL 'infinity years';
+                        ^
+SELECT INTERVAL 'infinity ago';
+ERROR:  invalid input syntax for type interval: "infinity ago"
+LINE 1: SELECT INTERVAL 'infinity ago';
+                        ^
+SELECT INTERVAL '+infinity -infinity';
+ERROR:  invalid input syntax for type interval: "+infinity -infinity"
+LINE 1: SELECT INTERVAL '+infinity -infinity';
+                        ^
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index c64bcb7c12..835f0e5762 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2125,3 +2125,65 @@ select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '-infinity';
+ERROR:  interval out of range
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp 'infinity', timestamp 'infinity');
+ERROR:  interval out of range
+select age(timestamp 'infinity', timestamp '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+select age(timestamp '-infinity', timestamp '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 2ca2101dd4..a084357480 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2468,6 +2468,10 @@ select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
 ERROR:  step size cannot equal zero
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+ERROR:  step size cannot be infinite
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
+ERROR:  step size cannot be infinite
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
 SELECT date_add('2022-10-30 00:00:00+01'::timestamptz,
@@ -3210,3 +3214,61 @@ select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
  Tue Jan 17 16:00:00 2017 PST
 (1 row)
 
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+ERROR:  interval out of range
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column? 
+----------
+ infinity
+(1 row)
+
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+ ?column?  
+-----------
+ -infinity
+(1 row)
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+ERROR:  interval out of range
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+   age    
+----------
+ infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+    age    
+-----------
+ -infinity
+(1 row)
+
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+ERROR:  interval out of range
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index 69a38df10b..2201740c18 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -2372,6 +2372,7 @@ create temp table datetimes(
     f_timestamp timestamp
 );
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -2381,14 +2382,16 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_time range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
-  1 | 11:00:00 |           1 |          3
+  0 | 10:00:00 |           0 |          2
+  1 | 11:00:00 |           0 |          3
   2 | 12:00:00 |           1 |          4
   3 | 13:00:00 |           2 |          6
   4 | 14:00:00 |           3 |          6
@@ -2396,9 +2399,10 @@ window w as (order by f_time range between
   6 | 15:00:00 |           4 |          7
   7 | 17:00:00 |           7 |          9
   8 | 18:00:00 |           7 |         10
-  9 | 19:00:00 |           8 |         10
- 10 | 20:00:00 |           9 |         10
-(10 rows)
+  9 | 19:00:00 |           8 |         11
+ 10 | 20:00:00 |           9 |         11
+ 11 | 21:00:00 |          10 |         11
+(12 rows)
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2406,7 +2410,8 @@ window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_time  | first_value | last_value 
 ----+----------+-------------+------------
- 10 | 20:00:00 |          10 |          8
+ 11 | 21:00:00 |          11 |          9
+ 10 | 20:00:00 |          11 |          8
   9 | 19:00:00 |          10 |          7
   8 | 18:00:00 |           9 |          7
   7 | 17:00:00 |           8 |          5
@@ -2414,17 +2419,90 @@ window w as (order by f_time desc range between
   5 | 15:00:00 |           6 |          3
   4 | 14:00:00 |           6 |          2
   3 | 13:00:00 |           4 |          1
-  2 | 12:00:00 |           3 |          1
-  1 | 11:00:00 |           2 |          1
-(10 rows)
+  2 | 12:00:00 |           3 |          0
+  1 | 11:00:00 |           2 |          0
+  0 | 10:00:00 |           1 |          0
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |           0 |         11
+  1 | 11:00:00 |           0 |         11
+  2 | 12:00:00 |           0 |         11
+  3 | 13:00:00 |           0 |         11
+  4 | 14:00:00 |           0 |         11
+  5 | 15:00:00 |           0 |         11
+  6 | 15:00:00 |           0 |         11
+  7 | 17:00:00 |           0 |         11
+  8 | 18:00:00 |           0 |         11
+  9 | 19:00:00 |           0 |         11
+ 10 | 20:00:00 |           0 |         11
+ 11 | 21:00:00 |           0 |         11
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_time  | first_value | last_value 
+----+----------+-------------+------------
+  0 | 10:00:00 |             |           
+  1 | 11:00:00 |             |           
+  2 | 12:00:00 |             |           
+  3 | 13:00:00 |             |           
+  4 | 14:00:00 |             |           
+  5 | 15:00:00 |             |           
+  6 | 15:00:00 |             |           
+  7 | 17:00:00 |             |           
+  8 | 18:00:00 |             |           
+  9 | 19:00:00 |             |           
+ 10 | 20:00:00 |             |           
+ 11 | 21:00:00 |             |           
+(12 rows)
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
              '70 min'::interval preceding and '2 hours'::interval following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
-  1 | 11:00:00+01 |           1 |          3
+  0 | 10:00:00+01 |           0 |          2
+  1 | 11:00:00+01 |           0 |          3
   2 | 12:00:00+01 |           1 |          4
   3 | 13:00:00+01 |           2 |          6
   4 | 14:00:00+01 |           3 |          6
@@ -2432,9 +2510,10 @@ window w as (order by f_timetz range between
   6 | 15:00:00+01 |           4 |          7
   7 | 17:00:00+01 |           7 |          9
   8 | 18:00:00+01 |           7 |         10
-  9 | 19:00:00+01 |           8 |         10
- 10 | 20:00:00+01 |           9 |         10
-(10 rows)
+  9 | 19:00:00+01 |           8 |         11
+ 10 | 20:00:00+01 |           9 |         11
+ 11 | 21:00:00+01 |          10 |         11
+(12 rows)
 
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2442,7 +2521,8 @@ window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
  id |  f_timetz   | first_value | last_value 
 ----+-------------+-------------+------------
- 10 | 20:00:00+01 |          10 |          8
+ 11 | 21:00:00+01 |          11 |          9
+ 10 | 20:00:00+01 |          11 |          8
   9 | 19:00:00+01 |          10 |          7
   8 | 18:00:00+01 |           9 |          7
   7 | 17:00:00+01 |           8 |          5
@@ -2450,16 +2530,89 @@ window w as (order by f_timetz desc range between
   5 | 15:00:00+01 |           6 |          3
   4 | 14:00:00+01 |           6 |          2
   3 | 13:00:00+01 |           4 |          1
-  2 | 12:00:00+01 |           3 |          1
-  1 | 11:00:00+01 |           2 |          1
-(10 rows)
+  2 | 12:00:00+01 |           3 |          0
+  1 | 11:00:00+01 |           2 |          0
+  0 | 10:00:00+01 |           1 |          0
+(12 rows)
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |           0 |         11
+  1 | 11:00:00+01 |           0 |         11
+  2 | 12:00:00+01 |           0 |         11
+  3 | 13:00:00+01 |           0 |         11
+  4 | 14:00:00+01 |           0 |         11
+  5 | 15:00:00+01 |           0 |         11
+  6 | 15:00:00+01 |           0 |         11
+  7 | 17:00:00+01 |           0 |         11
+  8 | 18:00:00+01 |           0 |         11
+  9 | 19:00:00+01 |           0 |         11
+ 10 | 20:00:00+01 |           0 |         11
+ 11 | 21:00:00+01 |           0 |         11
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |  f_timetz   | first_value | last_value 
+----+-------------+-------------+------------
+  0 | 10:00:00+01 |             |           
+  1 | 11:00:00+01 |             |           
+  2 | 12:00:00+01 |             |           
+  3 | 13:00:00+01 |             |           
+  4 | 14:00:00+01 |             |           
+  5 | 15:00:00+01 |             |           
+  6 | 15:00:00+01 |             |           
+  7 | 17:00:00+01 |             |           
+  8 | 18:00:00+01 |             |           
+  9 | 19:00:00+01 |             |           
+ 10 | 20:00:00+01 |             |           
+ 11 | 21:00:00+01 |             |           
+(12 rows)
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
              '1 year'::interval preceding and '1 year'::interval following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
   1 | @ 1 year   |           1 |          2
   2 | @ 2 years  |           1 |          3
   3 | @ 3 years  |           2 |          4
@@ -2470,7 +2623,8 @@ window w as (order by f_interval range between
   8 | @ 8 years  |           7 |          9
   9 | @ 9 years  |           8 |         10
  10 | @ 10 years |           9 |         10
-(10 rows)
+ 11 | infinity   |          11 |         11
+(12 rows)
 
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2478,6 +2632,7 @@ window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
  id | f_interval | first_value | last_value 
 ----+------------+-------------+------------
+ 11 | infinity   |          11 |         11
  10 | @ 10 years |          10 |          9
   9 | @ 9 years  |          10 |          8
   8 | @ 8 years  |           9 |          7
@@ -2488,14 +2643,87 @@ window w as (order by f_interval desc range between
   3 | @ 3 years  |           4 |          2
   2 | @ 2 years  |           3 |          1
   1 | @ 1 year   |           2 |          1
-(10 rows)
+  0 | -infinity  |           0 |          0
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |           0 |         11
+  2 | @ 2 years  |           0 |         11
+  3 | @ 3 years  |           0 |         11
+  4 | @ 4 years  |           0 |         11
+  5 | @ 5 years  |           0 |         11
+  6 | @ 5 years  |           0 |         11
+  7 | @ 7 years  |           0 |         11
+  8 | @ 8 years  |           0 |         11
+  9 | @ 9 years  |           0 |         11
+ 10 | @ 10 years |           0 |         11
+ 11 | infinity   |           0 |         11
+(12 rows)
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |          0
+  1 | @ 1 year   |           0 |          0
+  2 | @ 2 years  |           0 |          0
+  3 | @ 3 years  |           0 |          0
+  4 | @ 4 years  |           0 |          0
+  5 | @ 5 years  |           0 |          0
+  6 | @ 5 years  |           0 |          0
+  7 | @ 7 years  |           0 |          0
+  8 | @ 8 years  |           0 |          0
+  9 | @ 9 years  |           0 |          0
+ 10 | @ 10 years |           0 |          0
+ 11 | infinity   |           0 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id | f_interval | first_value | last_value 
+----+------------+-------------+------------
+  0 | -infinity  |           0 |         11
+  1 | @ 1 year   |          11 |         11
+  2 | @ 2 years  |          11 |         11
+  3 | @ 3 years  |          11 |         11
+  4 | @ 4 years  |          11 |         11
+  5 | @ 5 years  |          11 |         11
+  6 | @ 5 years  |          11 |         11
+  7 | @ 7 years  |          11 |         11
+  8 | @ 8 years  |          11 |         11
+  9 | @ 9 years  |          11 |         11
+ 10 | @ 10 years |          11 |         11
+ 11 | infinity   |          11 |         11
+(12 rows)
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
   1 | Thu Oct 19 02:23:54 2000 PDT |           1 |          3
   2 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
   3 | Fri Oct 19 02:23:54 2001 PDT |           1 |          4
@@ -2506,7 +2734,8 @@ window w as (order by f_timestamptz range between
   8 | Thu Oct 19 02:23:54 2006 PDT |           7 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |           8 |         10
  10 | Sun Oct 19 02:23:54 2008 PDT |           9 |         10
-(10 rows)
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2514,6 +2743,7 @@ window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
  id |        f_timestamptz         | first_value | last_value 
 ----+------------------------------+-------------+------------
+ 11 | infinity                     |          11 |         11
  10 | Sun Oct 19 02:23:54 2008 PDT |          10 |          9
   9 | Fri Oct 19 02:23:54 2007 PDT |          10 |          8
   8 | Thu Oct 19 02:23:54 2006 PDT |           9 |          7
@@ -2524,14 +2754,87 @@ window w as (order by f_timestamptz desc range between
   3 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   2 | Fri Oct 19 02:23:54 2001 PDT |           4 |          1
   1 | Thu Oct 19 02:23:54 2000 PDT |           3 |          1
-(10 rows)
+  0 | -infinity                    |           0 |          0
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |         11
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |          0
+  1 | Thu Oct 19 02:23:54 2000 PDT |           0 |          0
+  2 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  3 | Fri Oct 19 02:23:54 2001 PDT |           0 |          0
+  4 | Sat Oct 19 02:23:54 2002 PDT |           0 |          0
+  5 | Sun Oct 19 02:23:54 2003 PDT |           0 |          0
+  6 | Tue Oct 19 02:23:54 2004 PDT |           0 |          0
+  7 | Wed Oct 19 02:23:54 2005 PDT |           0 |          0
+  8 | Thu Oct 19 02:23:54 2006 PDT |           0 |          0
+  9 | Fri Oct 19 02:23:54 2007 PDT |           0 |          0
+ 10 | Sun Oct 19 02:23:54 2008 PDT |           0 |          0
+ 11 | infinity                     |           0 |         11
+(12 rows)
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |        f_timestamptz         | first_value | last_value 
+----+------------------------------+-------------+------------
+  0 | -infinity                    |           0 |         11
+  1 | Thu Oct 19 02:23:54 2000 PDT |          11 |         11
+  2 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  3 | Fri Oct 19 02:23:54 2001 PDT |          11 |         11
+  4 | Sat Oct 19 02:23:54 2002 PDT |          11 |         11
+  5 | Sun Oct 19 02:23:54 2003 PDT |          11 |         11
+  6 | Tue Oct 19 02:23:54 2004 PDT |          11 |         11
+  7 | Wed Oct 19 02:23:54 2005 PDT |          11 |         11
+  8 | Thu Oct 19 02:23:54 2006 PDT |          11 |         11
+  9 | Fri Oct 19 02:23:54 2007 PDT |          11 |         11
+ 10 | Sun Oct 19 02:23:54 2008 PDT |          11 |         11
+ 11 | infinity                     |          11 |         11
+(12 rows)
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
              '1 year'::interval preceding and '1 year'::interval following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
   1 | Thu Oct 19 10:23:54 2000 |           1 |          3
   2 | Fri Oct 19 10:23:54 2001 |           1 |          4
   3 | Fri Oct 19 10:23:54 2001 |           1 |          4
@@ -2542,7 +2845,8 @@ window w as (order by f_timestamp range between
   8 | Thu Oct 19 10:23:54 2006 |           7 |          9
   9 | Fri Oct 19 10:23:54 2007 |           8 |         10
  10 | Sun Oct 19 10:23:54 2008 |           9 |         10
-(10 rows)
+ 11 | infinity                 |          11 |         11
+(12 rows)
 
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -2550,6 +2854,7 @@ window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
  id |       f_timestamp        | first_value | last_value 
 ----+--------------------------+-------------+------------
+ 11 | infinity                 |          11 |         11
  10 | Sun Oct 19 10:23:54 2008 |          10 |          9
   9 | Fri Oct 19 10:23:54 2007 |          10 |          8
   8 | Thu Oct 19 10:23:54 2006 |           9 |          7
@@ -2560,8 +2865,80 @@ window w as (order by f_timestamp desc range between
   3 | Fri Oct 19 10:23:54 2001 |           4 |          1
   2 | Fri Oct 19 10:23:54 2001 |           4 |          1
   1 | Thu Oct 19 10:23:54 2000 |           3 |          1
-(10 rows)
+  0 | -infinity                |           0 |          0
+(12 rows)
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |           0 |         11
+  2 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  3 | Fri Oct 19 10:23:54 2001 |           0 |         11
+  4 | Sat Oct 19 10:23:54 2002 |           0 |         11
+  5 | Sun Oct 19 10:23:54 2003 |           0 |         11
+  6 | Tue Oct 19 10:23:54 2004 |           0 |         11
+  7 | Wed Oct 19 10:23:54 2005 |           0 |         11
+  8 | Thu Oct 19 10:23:54 2006 |           0 |         11
+  9 | Fri Oct 19 10:23:54 2007 |           0 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |         11
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |          0
+  1 | Thu Oct 19 10:23:54 2000 |           0 |          0
+  2 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  3 | Fri Oct 19 10:23:54 2001 |           0 |          0
+  4 | Sat Oct 19 10:23:54 2002 |           0 |          0
+  5 | Sun Oct 19 10:23:54 2003 |           0 |          0
+  6 | Tue Oct 19 10:23:54 2004 |           0 |          0
+  7 | Wed Oct 19 10:23:54 2005 |           0 |          0
+  8 | Thu Oct 19 10:23:54 2006 |           0 |          0
+  9 | Fri Oct 19 10:23:54 2007 |           0 |          0
+ 10 | Sun Oct 19 10:23:54 2008 |           0 |          0
+ 11 | infinity                 |           0 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+ id |       f_timestamp        | first_value | last_value 
+----+--------------------------+-------------+------------
+  0 | -infinity                |           0 |         11
+  1 | Thu Oct 19 10:23:54 2000 |          11 |         11
+  2 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  3 | Fri Oct 19 10:23:54 2001 |          11 |         11
+  4 | Sat Oct 19 10:23:54 2002 |          11 |         11
+  5 | Sun Oct 19 10:23:54 2003 |          11 |         11
+  6 | Tue Oct 19 10:23:54 2004 |          11 |         11
+  7 | Wed Oct 19 10:23:54 2005 |          11 |         11
+  8 | Thu Oct 19 10:23:54 2006 |          11 |         11
+  9 | Fri Oct 19 10:23:54 2007 |          11 |         11
+ 10 | Sun Oct 19 10:23:54 2008 |          11 |         11
+ 11 | infinity                 |          11 |         11
+(12 rows)
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+ERROR:  invalid preceding or following size in window function
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -4375,6 +4752,52 @@ SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDE
  4 | 
 (4 rows)
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+                                      x                                       |   curr_next_avg   |   prev_curr_avg   | curr_next_sum | prev_curr_sum 
+------------------------------------------------------------------------------+-------------------+-------------------+---------------+---------------
+                                                                              | infinity          |                   | infinity      | 
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 178956970 years 8 mons 2147483648 days 2562047788 hours 54.775807 secs ago | -infinity         | infinity          | -infinity     | infinity
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+ @ 178956970 years 7 mons 2147483647 days 2562047788 hours 54.775806 secs     | infinity          | -infinity         | infinity      | -infinity
+ infinity                                                                     | infinity          | infinity          | infinity      | infinity
+ @ 6 days                                                                     | @ 6 days 12 hours | infinity          | @ 13 days     | infinity
+ @ 7 days                                                                     | @ 7 days          | @ 6 days 12 hours | @ 7 days      | @ 13 days
+                                                                              | -infinity         | @ 7 days          | -infinity     | @ 7 days
+ -infinity                                                                    | -infinity         | -infinity         | -infinity     | -infinity
+(10 rows)
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+ERROR:  interval out of range.
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum 
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index b666dbad67..116106d30f 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -682,6 +682,25 @@ SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
 EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
 SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
 
+DROP TABLE brin_interval_test;
+RESET enable_seqscan;
+
+-- test handling of infinite interval values
+CREATE TABLE brin_interval_test(a INTERVAL);
+
+INSERT INTO brin_interval_test VALUES ('-infinity'), ('infinity');
+INSERT INTO brin_interval_test SELECT (i || ' days')::interval FROM generate_series(100, 140) s(i);
+
+CREATE INDEX ON brin_interval_test USING brin (a interval_minmax_multi_ops) WITH (pages_per_range=1);
+
+SET enable_seqscan = off;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '-30 years'::interval;
+
+EXPLAIN (ANALYZE, TIMING OFF, COSTS OFF, SUMMARY OFF)
+SELECT * FROM brin_interval_test WHERE a = '30 years'::interval;
+
 DROP TABLE brin_interval_test;
 RESET enable_seqscan;
 RESET datestyle;
diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql
index 39a35a6b7c..252bce4b1c 100644
--- a/src/test/regress/sql/horology.sql
+++ b/src/test/regress/sql/horology.sql
@@ -213,10 +213,12 @@ SELECT t.d1 AS t, i.f1 AS i, t.d1 + i.f1 AS "add", t.d1 - i.f1 AS "subtract"
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIME_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 SELECT t.f1 AS t, i.f1 AS i, t.f1 + i.f1 AS "add", t.f1 - i.f1 AS "subtract"
   FROM TIMETZ_TBL t, INTERVAL_TBL i
+  WHERE isfinite(i.f1)
   ORDER BY 1,2;
 
 -- SQL9x OVERLAPS operator
@@ -293,7 +295,6 @@ SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 + t.f1 AS plus
 
 SELECT d.f1 AS "timestamp", t.f1 AS "interval", d.f1 - t.f1 AS minus
   FROM TEMP_TIMESTAMP d, INTERVAL_TBL t
-  WHERE isfinite(d.f1)
   ORDER BY minus, "timestamp", "interval";
 
 SELECT d.f1 AS "timestamp",
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index a0a373f08b..caad291890 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -14,6 +14,8 @@ SELECT INTERVAL '-1 days +02:03' AS "22 hours ago...";
 SELECT INTERVAL '1.5 weeks' AS "Ten days twelve hours";
 SELECT INTERVAL '1.5 months' AS "One month 15 days";
 SELECT INTERVAL '10 years -11 month -12 days +13:14' AS "9 years...";
+SELECT INTERVAL 'infinity' AS "eternity";
+SELECT INTERVAL '-infinity' AS "beginning of time";
 
 CREATE TABLE INTERVAL_TBL (f1 interval);
 
@@ -27,6 +29,8 @@ INSERT INTO INTERVAL_TBL (f1) VALUES ('1 day 2 hours 3 minutes 4 seconds');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('6 years');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months');
 INSERT INTO INTERVAL_TBL (f1) VALUES ('5 months 12 hours');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('infinity');
+INSERT INTO INTERVAL_TBL (f1) VALUES ('-infinity');
 
 -- badly formatted interval
 INSERT INTO INTERVAL_TBL (f1) VALUES ('badly formatted interval');
@@ -66,6 +70,17 @@ SELECT r1.*, r2.*
    WHERE r1.f1 > r2.f1
    ORDER BY r1.f1, r2.f1;
 
+-- test unary minus
+
+SELECT f1, -f1 FROM INTERVAL_TBL;
+SELECT -('-2147483648 months'::interval); -- should fail
+SELECT -('-2147483647 months'::interval); -- ok
+SELECT -('-2147483648 days'::interval); -- should fail
+SELECT -('-2147483647 days'::interval); -- ok
+SELECT -('-9223372036854775808 us'::interval); -- should fail
+SELECT -('-9223372036854775807 us'::interval); -- ok
+SELECT -('-2147483647 months -2147483647 days -9223372036854775807 us'::interval); -- should fail
+
 -- Test intervals that are large enough to overflow 64 bits in comparisons
 CREATE TEMP TABLE INTERVAL_TBL_OF (f1 interval);
 INSERT INTO INTERVAL_TBL_OF (f1) VALUES
@@ -95,6 +110,9 @@ SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 SELECT f1 FROM INTERVAL_TBL_OF r1 ORDER BY f1;
 RESET enable_seqscan;
 
+-- subtracting about-to-overflow values should result in 0
+SELECT f1 - f1 FROM INTERVAL_TBL_OF;
+
 DROP TABLE INTERVAL_TBL_OF;
 
 -- Test multiplication and division with intervals.
@@ -140,7 +158,7 @@ SELECT * FROM INTERVAL_TBL;
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval
 
-select avg(f1) from interval_tbl;
+select avg(f1) from interval_tbl where isfinite(f1);
 
 -- test long interval input
 select '4 millenniums 5 centuries 4 decades 1 year 4 months 4 days 17 minutes 31 seconds'::interval;
@@ -528,13 +546,13 @@ select make_interval(mins := -1, secs := -9223372036800.0);
 
 -- test that INT_MIN number is formatted properly
 SET IntervalStyle to postgres;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to sql_standard;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to iso_8601;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 SET IntervalStyle to postgres_verbose;
-select interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+select interval '-2147483647 months -2147483648 days -9223372036854775808 us';
 
 -- check that '30 days' equals '1 month' according to the hash function
 select '30 days'::interval = '1 month'::interval as t;
@@ -598,6 +616,157 @@ SELECT f1,
 -- internal overflow test case
 SELECT extract(epoch from interval '1000000000 days');
 
+--
+-- test infinite intervals
+--
+
+-- largest finite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775807 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775806 us';
+
+-- infinite intervals
+SELECT interval '-2147483648 months -2147483648 days -9223372036854775808 us';
+SELECT interval '2147483647 months 2147483647 days 9223372036854775807 us';
+
+CREATE TABLE INFINITE_INTERVAL_TBL (i interval);
+INSERT INTO INFINITE_INTERVAL_TBL VALUES ('infinity'), ('-infinity'), ('1 year 2 days 3 hours');
+
+SELECT i, isfinite(i) FROM INFINITE_INTERVAL_TBL;
+
+-- test basic arithmetic
+CREATE FUNCTION eval(expr text)
+RETURNS text AS
+$$
+DECLARE
+  result text;
+BEGIN
+  EXECUTE 'select '||expr INTO result;
+  RETURN result;
+EXCEPTION WHEN OTHERS THEN
+  RETURN SQLERRM;
+END
+$$
+LANGUAGE plpgsql;
+
+SELECT d AS date, i AS interval,
+       eval(format('date %L + interval %L', d, i)) AS plus,
+       eval(format('date %L - interval %L', d, i)) AS minus
+FROM (VALUES (date '-infinity'),
+             (date '1995-08-06'),
+             (date 'infinity')) AS t1(d),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT i1 AS interval1, i2 AS interval2,
+       eval(format('interval %L + interval %L', i1, i2)) AS plus,
+       eval(format('interval %L - interval %L', i1, i2)) AS minus
+FROM (VALUES (interval '-infinity'),
+             (interval '2 months'),
+             (interval 'infinity')) AS t1(i1),
+     (VALUES (interval '-infinity'),
+             (interval '10 days'),
+             (interval 'infinity')) AS t2(i2);
+
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' + interval '1 month 1 day 1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' + interval '-1 month -1 day -1 us';
+SELECT interval '2147483646 months 2147483646 days 9223372036854775806 us' - interval '-1 month -1 day -1 us';
+SELECT interval '-2147483647 months -2147483647 days -9223372036854775807 us' - interval '1 month 1 day 1 us';
+
+SELECT t AS timestamp, i AS interval,
+       eval(format('timestamp %L + interval %L', t, i)) AS plus,
+       eval(format('timestamp %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamp '-infinity'),
+             (timestamp '1995-08-06 12:30:15'),
+             (timestamp 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+SELECT t AT TIME ZONE 'GMT' AS timestamptz, i AS interval,
+       eval(format('timestamptz %L + interval %L', t, i)) AS plus,
+       eval(format('timestamptz %L - interval %L', t, i)) AS minus
+FROM (VALUES (timestamptz '-infinity'),
+             (timestamptz '1995-08-06 12:30:15 GMT'),
+             (timestamptz 'infinity')) AS t1(t),
+     (VALUES (interval '-infinity'),
+             (interval 'infinity')) AS t2(i);
+
+-- time +/- infinite interval not supported
+SELECT time '11:27:42' + interval 'infinity';
+SELECT time '11:27:42' + interval '-infinity';
+SELECT time '11:27:42' - interval 'infinity';
+SELECT time '11:27:42' - interval '-infinity';
+SELECT timetz '11:27:42' + interval 'infinity';
+SELECT timetz '11:27:42' + interval '-infinity';
+SELECT timetz '11:27:42' - interval 'infinity';
+SELECT timetz '11:27:42' - interval '-infinity';
+
+SELECT lhst.i lhs,
+    rhst.i rhs,
+    lhst.i < rhst.i AS lt,
+    lhst.i <= rhst.i AS le,
+    lhst.i = rhst.i AS eq,
+    lhst.i > rhst.i AS gt,
+    lhst.i >= rhst.i AS ge,
+    lhst.i <> rhst.i AS ne
+    FROM INFINITE_INTERVAL_TBL lhst CROSS JOIN INFINITE_INTERVAL_TBL rhst
+    WHERE NOT isfinite(lhst.i);
+
+SELECT i AS interval,
+    -i AS um,
+    i * 2.0 AS mul,
+    i * -2.0 AS mul_neg,
+    i * 'infinity' AS mul_inf,
+    i * '-infinity' AS mul_inf_neg,
+    i / 3.0 AS div,
+    i / -3.0 AS div_neg
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT -interval '-2147483647 months -2147483647 days -9223372036854775807 us';
+SELECT interval 'infinity' * 'nan';
+SELECT interval '-infinity' * 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' * 2;
+SELECT interval 'infinity' * 0;
+SELECT interval '-infinity' * 0;
+SELECT interval '0 days' * 'infinity'::float;
+SELECT interval '0 days' * '-infinity'::float;
+SELECT interval '5 days' * 'infinity'::float;
+SELECT interval '5 days' * '-infinity'::float;
+
+SELECT interval 'infinity' / 'infinity';
+SELECT interval 'infinity' / '-infinity';
+SELECT interval 'infinity' / 'nan';
+SELECT interval '-infinity' / 'infinity';
+SELECT interval '-infinity' / '-infinity';
+SELECT interval '-infinity' / 'nan';
+SELECT interval '-1073741824 months -1073741824 days -4611686018427387904 us' / 0.5;
+
+SELECT date_bin('infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+SELECT date_bin('-infinity', timestamp '2001-02-16 20:38:40', timestamp '2001-02-16 20:05:00');
+
+SELECT i AS interval, date_trunc('hour', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamp);
+SELECT timezone('infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('-infinity'::interval, '1995-08-06 12:12:12'::timestamptz);
+SELECT timezone('infinity'::interval, '12:12:12'::time);
+SELECT timezone('-infinity'::interval, '12:12:12'::time);
+SELECT timezone('infinity'::interval, '12:12:12'::timetz);
+SELECT timezone('-infinity'::interval, '12:12:12'::timetz);
+
+SELECT 'infinity'::interval::time;
+SELECT '-infinity'::interval::time;
+
+SELECT to_char('infinity'::interval, 'YYYY');
+SELECT to_char('-infinity'::interval, 'YYYY');
+
 -- "ago" can only appear once at the end of an interval.
 SELECT INTERVAL '42 days 2 seconds ago ago';
 SELECT INTERVAL '2 minutes ago 5 days';
@@ -605,3 +774,17 @@ SELECT INTERVAL '2 minutes ago 5 days';
 -- consecutive and dangling units are not allowed.
 SELECT INTERVAL 'hour 5 months';
 SELECT INTERVAL '1 year months days 5 hours';
+
+-- unacceptable reserved words in interval. Only "infinity", "+infinity" and
+-- "-infinity" are allowed.
+SELECT INTERVAL 'now';
+SELECT INTERVAL 'today';
+SELECT INTERVAL 'tomorrow';
+SELECT INTERVAL 'allballs';
+SELECT INTERVAL 'epoch';
+SELECT INTERVAL 'yesterday';
+
+-- infinity specification should be the only thing
+SELECT INTERVAL 'infinity years';
+SELECT INTERVAL 'infinity ago';
+SELECT INTERVAL '+infinity -infinity';
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index b9bcce9cfe..ea12ffd18d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -397,3 +397,22 @@ select generate_series('2022-01-01 00:00'::timestamp,
 select * from generate_series('2020-01-01 00:00'::timestamp,
                               '2020-01-02 03:00'::timestamp,
                               '0 hour'::interval);
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamp '1995-08-06 12:12:12', timestamp '1996-08-06 12:12:12', interval '-infinity');
+
+
+-- test arithmetic with infinite timestamps
+select timestamp 'infinity' - timestamp 'infinity';
+select timestamp 'infinity' - timestamp '-infinity';
+select timestamp '-infinity' - timestamp 'infinity';
+select timestamp '-infinity' - timestamp '-infinity';
+select timestamp 'infinity' - timestamp '1995-08-06 12:12:12';
+select timestamp '-infinity' - timestamp '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+select age(timestamp 'infinity');
+select age(timestamp '-infinity');
+select age(timestamp 'infinity', timestamp 'infinity');
+select age(timestamp 'infinity', timestamp '-infinity');
+select age(timestamp '-infinity', timestamp 'infinity');
+select age(timestamp '-infinity', timestamp '-infinity');
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index cdc57bc160..a2dcd5f5d8 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -458,6 +458,8 @@ select generate_series('2022-01-01 00:00'::timestamptz,
 select * from generate_series('2020-01-01 00:00'::timestamptz,
                               '2020-01-02 03:00'::timestamptz,
                               '0 hour'::interval);
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval 'infinity');
+select generate_series(timestamptz '1995-08-06 12:12:12', timestamptz '1996-08-06 12:12:12', interval '-infinity');
 
 -- Interval crossing time shift for Europe/Warsaw timezone (with DST)
 SET TimeZone to 'UTC';
@@ -642,3 +644,19 @@ insert into tmptz values ('2017-01-18 00:00+00');
 explain (costs off)
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
 select * from tmptz where f1 at time zone 'utc' = '2017-01-18 00:00';
+
+-- test arithmetic with infinite timestamps
+SELECT timestamptz 'infinity' - timestamptz 'infinity';
+SELECT timestamptz 'infinity' - timestamptz '-infinity';
+SELECT timestamptz '-infinity' - timestamptz 'infinity';
+SELECT timestamptz '-infinity' - timestamptz '-infinity';
+SELECT timestamptz 'infinity' - timestamptz '1995-08-06 12:12:12';
+SELECT timestamptz '-infinity' - timestamptz '1995-08-06 12:12:12';
+
+-- test age() with infinite timestamps
+SELECT age(timestamptz 'infinity');
+SELECT age(timestamptz '-infinity');
+SELECT age(timestamptz 'infinity', timestamptz 'infinity');
+SELECT age(timestamptz 'infinity', timestamptz '-infinity');
+SELECT age(timestamptz '-infinity', timestamptz 'infinity');
+SELECT age(timestamptz '-infinity', timestamptz '-infinity');
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 9113a92ae0..437e948d6c 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -673,6 +673,7 @@ create temp table datetimes(
 );
 
 insert into datetimes values
+(0, '10:00', '10:00 BST', '-infinity', '-infinity', '-infinity'),
 (1, '11:00', '11:00 BST', '1 year', '2000-10-19 10:23:54+01', '2000-10-19 10:23:54'),
 (2, '12:00', '12:00 BST', '2 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
 (3, '13:00', '13:00 BST', '3 years', '2001-10-19 10:23:54+01', '2001-10-19 10:23:54'),
@@ -682,7 +683,8 @@ insert into datetimes values
 (7, '17:00', '17:00 BST', '7 years', '2005-10-19 10:23:54+01', '2005-10-19 10:23:54'),
 (8, '18:00', '18:00 BST', '8 years', '2006-10-19 10:23:54+01', '2006-10-19 10:23:54'),
 (9, '19:00', '19:00 BST', '9 years', '2007-10-19 10:23:54+01', '2007-10-19 10:23:54'),
-(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54');
+(10, '20:00', '20:00 BST', '10 years', '2008-10-19 10:23:54+01', '2008-10-19 10:23:54'),
+(11, '21:00', '21:00 BST', 'infinity', 'infinity', 'infinity');
 
 select id, f_time, first_value(id) over w, last_value(id) over w
 from datetimes
@@ -694,6 +696,32 @@ from datetimes
 window w as (order by f_time desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time desc range between
+             '-70 min' preceding and '2 hours' following);  -- error, negative offset disallowed
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_time, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_time range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timetz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timetz range between
@@ -704,6 +732,32 @@ from datetimes
 window w as (order by f_timetz desc range between
              '70 min' preceding and '2 hours' following);
 
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz desc range between
+             '70 min' preceding and '-2 hours' following);  -- error, negative offset disallowed
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timetz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timetz range between
+             'infinity'::interval following and
+             '-infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_interval, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_interval range between
@@ -714,6 +768,32 @@ from datetimes
 window w as (order by f_interval desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_interval, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_interval range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamptz, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamptz range between
@@ -724,6 +804,32 @@ from datetimes
 window w as (order by f_timestamptz desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz desc range between
+             '1 year' preceding and '-1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamptz, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamptz range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 select id, f_timestamp, first_value(id) over w, last_value(id) over w
 from datetimes
 window w as (order by f_timestamp range between
@@ -734,6 +840,32 @@ from datetimes
 window w as (order by f_timestamp desc range between
              '1 year' preceding and '1 year' following);
 
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp desc range between
+             '-1 year' preceding and '1 year' following);  -- error, negative offset disallowed
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval preceding and 'infinity'::interval preceding);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             'infinity'::interval following and 'infinity'::interval following);
+
+select id, f_timestamp, first_value(id) over w, last_value(id) over w
+from datetimes
+window w as (order by f_timestamp range between
+             '-infinity'::interval following and
+             'infinity'::interval following);  -- error, negative offset disallowed
+
 -- RANGE offset PRECEDING/FOLLOWING error cases
 select sum(salary) over (order by enroll_date, salary range between '1 year'::interval preceding and '2 years'::interval following
 	exclude ties), salary, enroll_date from empsalary;
@@ -1591,6 +1723,39 @@ SELECT i,AVG(v::numeric) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED
 SELECT i,AVG(v::interval) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,'1 sec'),(2,'2 sec'),(3,NULL),(4,NULL)) t(i,v);
 
+-- moving aggregates over infinite intervals
+SELECT  x
+        ,avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_avg
+        ,avg(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_avg
+        ,sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 1 FOLLOWING ) as curr_next_sum
+        ,sum(x) OVER(ROWS BETWEEN 1 PRECEDING AND CURRENT ROW ) as prev_curr_sum
+FROM (VALUES (NULL::interval),
+               ('infinity'::interval),
+               ('-2147483648 days -2147483648 months -9223372036854775807 usecs'), -- extreme interval value
+               ('-infinity'::interval),
+               ('2147483647 days 2147483647 months 9223372036854775806 usecs'), -- extreme interval value
+               ('infinity'::interval),
+               ('6 days'::interval),
+               ('7 days'::interval),
+               (NULL::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, avg(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
+--should fail.
+SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
+FROM (VALUES (NULL::interval),
+               ('3 days'::interval),
+               ('infinity'::timestamptz - now()),
+               ('6 days'::interval),
+               ('-infinity'::interval)) v(x);
+
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index bf50a32119..efc47bed10 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1205,6 +1205,7 @@ IntegerSet
 InternalDefaultACL
 InternalGrant
 Interval
+IntervalAggState
 IntoClause
 InvalMessageArray
 InvalidationMsgsGroup
-- 
2.35.3