From db692b0c84908b4ef5ea4c15fa2d742582ad2cf9 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 6 Oct 2021 13:38:42 -0400 Subject: [PATCH] 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 --- src/timezone/README | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/src/timezone/README b/src/timezone/README index f588d1f5add..dd5d5f9892a 100644 --- a/src/timezone/README +++ b/src/timezone/README @@ -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