timeofday() and clock_timestamp() produce different results when casting to timestamptz

On 03/23/2013 12:37 AM, Sergey Konoplev wrote:

Hi all,

Today after upgrading to 9.2 from 9.0 I faced a very odd
incompatibility that seems to me as a bug:

smoking_test=# select timeofday(), clock_timestamp();
timeofday | clock_timestamp
-------------------------------------+-------------------------------
Sat Mar 23 11:20:54.023796 2013 MSK | 2013-03-23 11:20:54.023815+04

smoking_test=# select timeofday()::timestamptz, clock_timestamp()::timestamptz;
timeofday | clock_timestamp
-------------------------------+-------------------------------
2013-03-23 12:21:03.995653+04 | 2013-03-23 11:21:03.995695+04

As you can see after casting timeofday() to timestamp with time zone
it adds one hour to the timestamp when clock_timestamp() behaves
normally.

Works for me on my time zone:

test=> select timeofday(), clock_timestamp();
timeofday | clock_timestamp
-------------------------------------+-------------------------------
Sat Mar 23 06:51:58.937533 2013 PDT | 2013-03-23 06:51:58.937579-07
(1 row)

test=> select timeofday()::timestamptz, clock_timestamp()::timestamptz;
timeofday | clock_timestamp
-------------------------------+-------------------------------
2013-03-23 06:52:14.547049-07 | 2013-03-23 06:52:14.547093-07

but not when I set to 'Europe/Moscow'

test=> set time zone 'Europe/Moscow';
SET
test=> select timeofday(), clock_timestamp();
timeofday | clock_timestamp
-------------------------------------+-------------------------------
Sat Mar 23 17:57:23.750469 2013 MSK | 2013-03-23 17:57:23.750495+04
(1 row)

test=> select timeofday()::timestamptz, clock_timestamp()::timestamptz;
timeofday | clock_timestamp
-------------------------------+-------------------------------
2013-03-23 18:57:31.529407+04 | 2013-03-23 17:57:31.529461+04
(1 row)

Seems the time zone info still thinks Moscow time is being setting
forward an hour for DST when in fact the time remains constant through
the year.

--
Sergey Konoplev
Database and Software Architect
http://www.linkedin.com/in/grayhemp

--
Adrian Klaver
adrian.klaver@gmail.com

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On 03/23/2013 12:37 AM, Sergey Konoplev wrote:

Hi all,

Today after upgrading to 9.2 from 9.0 I faced a very odd
incompatibility that seems to me as a bug:

smoking_test=# select timeofday(), clock_timestamp();
timeofday | clock_timestamp
-------------------------------------+-------------------------------
Sat Mar 23 11:20:54.023796 2013 MSK | 2013-03-23 11:20:54.023815+04

smoking_test=# select timeofday()::timestamptz, clock_timestamp()::timestamptz;
timeofday | clock_timestamp
-------------------------------+-------------------------------
2013-03-23 12:21:03.995653+04 | 2013-03-23 11:21:03.995695+04

As you can see after casting timeofday() to timestamp with time zone
it adds one hour to the timestamp when clock_timestamp() behaves
normally.

Sent my previous message too soon, to add:

Postgres seems to be aware of the DST status for Europe/Moscow(MSK):

test=> select * from pg_timezone_names where abbrev='MSK';

name | abbrev | utc_offset | is_dst

---------------+--------+------------+--------

Europe/Moscow | MSK | 04:00:00 | f

W-SU | MSK | 04:00:00 | f

test=> select * from pg_timezone_names where name='Europe/Moscow';
name | abbrev | utc_offset | is_dst
---------------+--------+------------+--------
Europe/Moscow | MSK | 04:00:00 | f
(1 row)

Would seem to mean the zoneinfo database is incorrect.

--
Sergey Konoplev
Database and Software Architect
http://www.linkedin.com/in/grayhemp

--
Adrian Klaver
adrian.klaver@gmail.com

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Adrian Klaver <adrian.klaver@gmail.com> writes:

Seems the time zone info still thinks Moscow time is being setting
forward an hour for DST when in fact the time remains constant through
the year.

I think the discrepancy is between this in timezone/data/europe:

Zone Europe/Moscow 2:30:20 - LMT 1880
2:30 - MMT 1916 Jul 3 # Moscow Mean Time
2:30:48 Russia %s 1919 Jul 1 2:00
3:00 Russia MSK/MSD 1922 Oct
2:00 - EET 1930 Jun 21
3:00 Russia MSK/MSD 1991 Mar 31 2:00s
2:00 Russia EE%sT 1992 Jan 19 2:00s
3:00 Russia MSK/MSD 2011 Mar 27 2:00s
4:00 - MSK

and this in timezone/tznames/Default:

MSD 14400 D # Moscow Daylight Time
# (Europe/Moscow)
MSK 10800 # Moscow Time
# (Europe/Moscow)

We really need to figure out a way to update the tznames data
automatically, or at least notice when it's become inconsistent with
the underlying Olson database.

regards, tom lane

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On 03/23/2013 08:16 AM, Tom Lane wrote:

Adrian Klaver <adrian.klaver@gmail.com> writes:

Seems the time zone info still thinks Moscow time is being setting
forward an hour for DST when in fact the time remains constant through
the year.

I think the discrepancy is between this in timezone/data/europe:

Zone Europe/Moscow 2:30:20 - LMT 1880
2:30 - MMT 1916 Jul 3 # Moscow Mean Time
2:30:48 Russia %s 1919 Jul 1 2:00
3:00 Russia MSK/MSD 1922 Oct
2:00 - EET 1930 Jun 21
3:00 Russia MSK/MSD 1991 Mar 31 2:00s
2:00 Russia EE%sT 1992 Jan 19 2:00s
3:00 Russia MSK/MSD 2011 Mar 27 2:00s
4:00 - MSK

and this in timezone/tznames/Default:

MSD 14400 D # Moscow Daylight Time
# (Europe/Moscow)
MSK 10800 # Moscow Time
# (Europe/Moscow)

We really need to figure out a way to update the tznames data
automatically, or at least notice when it's become inconsistent with
the underlying Olson database.

So I temporary fix would be to go into /share/timezonesets/Default

and change :

MSK 10800 # Moscow Time

to

MSK 14400 # Moscow Time

and then you get:

test=> set time zone 'Europe/Moscow';
SET
test=> select timeofday(), clock_timestamp();
timeofday | clock_timestamp
-------------------------------------+-------------------------------
Sun Mar 24 03:50:45.066537 2013 MSK | 2013-03-24 03:50:45.066582+04
(1 row)

test=> select timeofday()::timestamptz, clock_timestamp()::timestamptz;
timeofday | clock_timestamp
-------------------------------+-------------------------------
2013-03-24 03:50:52.485092+04 | 2013-03-24 03:50:52.485188+04
(1 row)

regards, tom lane

--
Adrian Klaver
adrian.klaver@gmail.com

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