postgresql/src/timezone
Tom Lane 3b91fe185a Update time zone abbreviation lists for changes missed since 2006.
Most (all?) of Russia has moved to what's effectively year-round daylight
savings time, so that the "standard" zone names now mean an hour later
than they used to.  Update that, notably changing MSK as per recent
complaint from Sergey Konoplev, but also CHOT, GET, IRKT, KGT, KRAT,
MAGT, NOVT, OMST, VLAT, YAKT, YEKT.  The corresponding DST abbreviations
are presumably now obsolete, but I left them in place with their old
definitions, just to reduce any possible breakage from this change.

Also add VOLT (Europe/Volgograd), which for some reason we never had
before, as well as MIST (Antarctica/Macquarie), and fix obsolete
definitions of MAWT, TKT, and WST.
2013-03-23 19:17:46 -04:00
..
data Update time zone data files to tzdata release 2012j. 2012-12-02 16:35:23 -05:00
tznames Update time zone abbreviation lists for changes missed since 2006. 2013-03-23 19:17:46 -04:00
.gitignore Semi-automatically detect changes in timezone abbreviations. 2013-03-23 19:17:44 -04:00
ialloc.c Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
known_abbrevs.txt Update time zone abbreviation lists for changes missed since 2006. 2013-03-23 19:17:46 -04:00
localtime.c Fix edge-case behavior of pg_next_dst_boundary(). 2012-04-25 17:26:10 -04:00
Makefile Semi-automatically detect changes in timezone abbreviations. 2013-03-23 19:17:44 -04:00
pgtz.c Update copyrights for 2013 2013-01-01 17:15:01 -05:00
pgtz.h Update copyrights for 2013 2013-01-01 17:15:01 -05:00
private.h Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
README Semi-automatically detect changes in timezone abbreviations. 2013-03-23 19:17:44 -04:00
scheck.c Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
strftime.c Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
tzfile.h Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
zic.c Semi-automatically detect changes in timezone abbreviations. 2013-03-23 19:17:44 -04:00

src/timezone/README

Timezone
========

This is a PostgreSQL adapted version of the timezone library from
http://www.iana.org/time-zones

The source code can be found at:

	ftp://ftp.iana.org/tz/releases/tzcode*.tar.gz

The code is currently synced with release 2010c.  There are many cosmetic
(and not so cosmetic) differences from the original tzcode library, but
diffs in the upstream version should usually be propagated to our version.

The data files under data/ are an exact copy of the latest data set from:

	ftp://ftp.iana.org/tz/releases/tzdata*.tar.gz

Since time zone rules change frequently in some parts of the world,
we should endeavor to update the data files before each PostgreSQL
release.

While the files under data/ can just be duplicated when updating, manual
effort is needed to update the time zone abbreviation lists under tznames/.
These need to be changed whenever new abbreviations are invented or the
UTC offset associated with an existing abbreviation changes.  To detect
if this has happened, after installing new files under data/ do
	gmake abbrevs.txt
which will produce a file showing all abbreviations that are in current
use according to the data/ files.  Compare this to known_abbrevs.txt,
which is the list that existed last time the tznames/ files were updated.
Update tznames/ as seems appropriate, then replace known_abbrevs.txt
in the same commit.

When there has been a new release of Windows (probably including Service
Packs), the list of matching timezones need to be updated. Run the
script in src/tools/win32tzlist.pl on a Windows machine running this new
release and apply any new timezones that it detects. Never remove any
mappings in case they are removed in Windows, since we still need to
match properly on the old version.