Doc: improve timezone/README's recipe for tracking Windows zones.

We should now cite CLDR as primary reference for the zone name
mapping.

Discussion: https://postgr.es/m/3266414.1633045628@sss.pgh.pa.us
This commit is contained in:
Tom Lane 2021-10-06 13:38:42 -04:00
parent e54a758d24
commit db692b0c84
1 changed files with 11 additions and 5 deletions

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@ -45,11 +45,17 @@ and pg_timezone_abbrevs views don't throw errors). It's worth running it
as a cross-check on proposed updates.
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.
Packs), findtimezone.c's mapping from Windows zones to IANA zones may
need to be updated. We have two approaches to doing this:
1. Consult the CLDR project's windowsZones.xml file, and add any zones
listed there that we don't have. Use their "territory=001" mapping
if there's more than one IANA zone listed.
2. Run the script in src/tools/win32tzlist.pl on a Windows machine
running the new release, and add any new timezones that it detects.
(This is not a full substitute for #1, though, as win32tzlist.pl
can't tell you which IANA zone to map to.)
In either case, never remove any zone names that have disappeared from
Windows, since we still need to match properly on older versions.
Time Zone code