Horton

Re: 002_types.pl fails on some timezones on windows

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrew Dunstan <andrew@dunslane.net>, Andres Freund <andres@anarazel.de>, pgsql-hackers <pgsql-hackers@postgresql.org>, Peter Eisentraut <peter_e@gmx.net>, Petr Jelinek <petr@2ndquadrant.com>
Date: 2021-10-02T21:23:39Z
Lists: pgsql-hackers 
On Sun, Oct 3, 2021 at 9:42 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> * Now-documented decision to map "Greenwich Standard Time"
> to Europe/London, not Atlantic/Reykjavik as they have it.

Hmm.  It's hard to pick a default from that set of merged zones, but
the funny thing about this choice is that Europe/London is the one
Olson zone that it's sure *not* to be, because then your system would
be using that other name, IIUC.

> * The miscellaneous deltas shown in the attached diff, which in
> many cases boil down to "we chose the first name mentioned for the
> zone, while CLDR did something else".  I felt that our historical
> mappings of these cases weren't wrong enough to justify any
> political flak I might take for changing them.  OTOH, maybe we
> should just say "we follow CLDR" and be done with it.

Eyeballing these, three look strange to me in a list of otherwise
city-based names: Pacific/Guam (instead of Port Moresby, capital of
PNG which apparently shares zone rules with the territory of Guam) and
Pacific/Samoa (country name instead of its capital Apia; the city
avoids any potential confusion with American Samoa which is on the
other side of the date line) and then "CET", an abbreviation.  But
debating individual points of geography and politics like this seems a
bit silly... I wasn't really aware of this Windows->Olson zone name
problem lurking in our tree before, but it sounds to me like switching
to 100% "we use CLDR, if you think it's wrong, please file a report at
cldr.unicode.org" wouldn't be a bad idea at all!

Commits

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

  2. Update our mapping of Windows time zone names some more.

  3. Update our mapping of Windows time zone names using CLDR info.

  4. Re-alphabetize the win32_tzmap[] array.

  5. Remove gratuitous environment dependency in 002_types.pl test.