mirror of
https://github.com/postgres/postgres.git
synced 2026-02-23 09:52:14 -05:00
6960277270
Add an option to zic.c to dump out all non-obsolete timezone abbreviations defined in the Olson database. Comparing this list to its previous state will clue us in when something happens that we may need to account for in the tznames/ time zone abbreviation lists. The README file's previous exhortation to "just grep for differences" was completely useless advice, in my now-considerable experience; but maybe this will be a bit more useful. As a starting point I built the same list from the tzdata files as they existed in 2006, which is committed here as known_abbrevs.txt. Comparison indeed turned up quite a few changes we had neglected to account for, which I will commit separately.
42 lines
1.7 KiB
Text
42 lines
1.7 KiB
Text
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.
|