diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index a7364f3..d262bda 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -24,6 +24,7 @@
 #include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
+#include "utils/formatting.h"
 #include "utils/lsyscache.h"
 #include "utils/json.h"
 #include "utils/jsonapi.h"
@@ -53,6 +54,8 @@ typedef enum					/* type categories for datum_to_json */
 	JSONTYPE_NULL,				/* null, so we didn't bother to identify */
 	JSONTYPE_BOOL,				/* boolean (built-in types only) */
 	JSONTYPE_NUMERIC,			/* numeric (ditto) */
+	JSONTYPE_TIMESTAMP,         /* we use special formatting for timestamp */
+	JSONTYPE_TIMESTAMPTZ,       /* ... and timestamptz */
 	JSONTYPE_JSON,				/* JSON itself (and JSONB) */
 	JSONTYPE_ARRAY,				/* array */
 	JSONTYPE_COMPOSITE,			/* composite */
@@ -60,6 +63,13 @@ typedef enum					/* type categories for datum_to_json */
 	JSONTYPE_OTHER				/* all else */
 } JsonTypeCategory;
 
+/*
+ * to_char formats to turn timestamps and timpstamptzs into json strings
+ * that are ISO 8601 compliant
+ */
+#define TS_ISO8601_FMT "\\\"YYYY-MM-DD\"T\"HH24:MI:SS.US\\\""
+#define TSTZ_ISO8601_FMT "\\\"YYYY-MM-DD\"T\"HH24:MI:SS.USOF\\\""
+
 static inline void json_lex(JsonLexContext *lex);
 static inline void json_lex_string(JsonLexContext *lex);
 static inline void json_lex_number(JsonLexContext *lex, char *s, bool *num_err);
@@ -1262,6 +1272,14 @@ json_categorize_type(Oid typoid,
 			*tcategory = JSONTYPE_NUMERIC;
 			break;
 
+		case TIMESTAMPOID:
+			*tcategory = JSONTYPE_TIMESTAMP;
+			break;
+
+		case TIMESTAMPTZOID:
+			*tcategory = JSONTYPE_TIMESTAMPTZ;
+			break;
+
 		case JSONOID:
 		case JSONBOID:
 			*tcategory = JSONTYPE_JSON;
@@ -1375,6 +1393,29 @@ datum_to_json(Datum val, bool is_null, StringInfo result,
 			}
 			pfree(outputstr);
 			break;
+		case JSONTYPE_TIMESTAMP:
+			/* 
+			 * The timestamp format used here provides for quoting the string, 
+			 * so no escaping is required.
+			 */
+			jsontext = DatumGetTextP(
+				DirectFunctionCall2(timestamp_to_char, val, 
+									CStringGetTextDatum(TS_ISO8601_FMT)));
+			outputstr = text_to_cstring(jsontext);
+			appendStringInfoString(result, outputstr);
+			pfree(outputstr);
+			pfree(jsontext);
+			break;
+		case JSONTYPE_TIMESTAMPTZ:
+			/* same comment as for timestamp above */
+			jsontext = DatumGetTextP(
+				DirectFunctionCall2(timestamptz_to_char, val, 
+									CStringGetTextDatum(TSTZ_ISO8601_FMT)));
+			outputstr = text_to_cstring(jsontext);
+			appendStringInfoString(result, outputstr);
+			pfree(outputstr);
+			pfree(jsontext);
+			break;
 		case JSONTYPE_JSON:
 			/* JSON and JSONB output will already be escaped */
 			outputstr = OidOutputFunctionCall(outfuncoid, val);
diff --git a/src/test/regress/expected/json.out b/src/test/regress/expected/json.out
index 9f08676..c4dc8b0 100644
--- a/src/test/regress/expected/json.out
+++ b/src/test/regress/expected/json.out
@@ -403,6 +403,29 @@ SELECT row_to_json(row((select array_agg(x) as d from generate_series(5,10) x)),
  {"f1":[5,6,7,8,9,10]}
 (1 row)
 
+-- to_json, timestamps
+select to_json(timestamp '2014-05-28 12:22:35.614298');
+           to_json            
+------------------------------
+ "2014-05-28T12:22:35.614298"
+(1 row)
+
+BEGIN;
+SET LOCAL TIME ZONE 10.5;
+select to_json(timestamptz '2014-05-28 12:22:35.614298-04');
+              to_json               
+------------------------------------
+ "2014-05-29T02:52:35.614298+10:30"
+(1 row)
+
+SET LOCAL TIME ZONE -8;
+select to_json(timestamptz '2014-05-28 12:22:35.614298-04');
+             to_json             
+---------------------------------
+ "2014-05-28T08:22:35.614298-08"
+(1 row)
+
+COMMIT;
 --json_agg
 SELECT json_agg(q)
   FROM ( SELECT $$a$$ || x AS b, y AS c,
diff --git a/src/test/regress/expected/json_1.out b/src/test/regress/expected/json_1.out
index 13f7687..629e98e 100644
--- a/src/test/regress/expected/json_1.out
+++ b/src/test/regress/expected/json_1.out
@@ -403,6 +403,29 @@ SELECT row_to_json(row((select array_agg(x) as d from generate_series(5,10) x)),
  {"f1":[5,6,7,8,9,10]}
 (1 row)
 
+-- to_json, timestamps
+select to_json(timestamp '2014-05-28 12:22:35.614298');
+           to_json            
+------------------------------
+ "2014-05-28T12:22:35.614298"
+(1 row)
+
+BEGIN;
+SET LOCAL TIME ZONE 10.5;
+select to_json(timestamptz '2014-05-28 12:22:35.614298-04');
+              to_json               
+------------------------------------
+ "2014-05-29T02:52:35.614298+10:30"
+(1 row)
+
+SET LOCAL TIME ZONE -8;
+select to_json(timestamptz '2014-05-28 12:22:35.614298-04');
+             to_json             
+---------------------------------
+ "2014-05-28T08:22:35.614298-08"
+(1 row)
+
+COMMIT;
 --json_agg
 SELECT json_agg(q)
   FROM ( SELECT $$a$$ || x AS b, y AS c,
diff --git a/src/test/regress/sql/json.sql b/src/test/regress/sql/json.sql
index 2ae5b82..6c2faec 100644
--- a/src/test/regress/sql/json.sql
+++ b/src/test/regress/sql/json.sql
@@ -100,6 +100,17 @@ FROM rows q;
 
 SELECT row_to_json(row((select array_agg(x) as d from generate_series(5,10) x)),false);
 
+-- to_json, timestamps
+
+select to_json(timestamp '2014-05-28 12:22:35.614298');
+
+BEGIN;
+SET LOCAL TIME ZONE 10.5;
+select to_json(timestamptz '2014-05-28 12:22:35.614298-04');
+SET LOCAL TIME ZONE -8;
+select to_json(timestamptz '2014-05-28 12:22:35.614298-04');
+COMMIT;
+
 --json_agg
 
 SELECT json_agg(q)