Horton

Re: UCT (Re: pgsql: Update time zone data files to tzdata release 2019a.)

Christopher Browne <cbbrowne@gmail.com>

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From: Christopher Browne <cbbrowne@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrew Gierth <andrew@tao11.riddles.org.uk>, Christoph Berg <myon@debian.org>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2019-06-14T20:29:34Z
Lists: pgsql-hackers 
On Fri, Jun 14, 2019, 3:12 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:

> A possibly better idea is to push back on tzdb's choice to unify
> these zones.   Don't know if they'd listen, but we could try.  The
> UCT symlink hasn't been out there so long that it's got much inertia.


One oddity; AIX had a preference for CUT with fallbacks to CUT0 and UCT
back when we had AIX boxes (5.2 or 5.3, if my memory still works on this).

We wound up setting PGTZ explicitly to UTC to overrule any such fighting
between time zones.

There may therefore be some older history (and some sort of inertia) in AIX
land than meets the eye elsewhere.

That doesn't prevent it from being a good idea to talk to tzdb maintainers,
of course.

Commits

  1. Tweak our special-case logic for the IANA "Factory" timezone.

  2. Avoid choosing "localtime" or "posixrules" as TimeZone during initdb.

  3. Prefer timezone name "UTC" over alternative spellings.

  4. Attempt to identify system timezone by reading /etc/localtime symlink.

  5. Update time zone data files to tzdata release 2019a.