Re: Bug in timezone-parsing?

villeja(at)avoltus(dot)com writes:
> I found a problem with the parsing of timezone-offsets in the current
> PG-driver. It seems something weird happened between 1921 and 1922, as the
> offset changes from hour-precision to second-precision:

> postgres=> select '1921-01-01'::timestamptz, '1922-01-01'::timestamptz;
> timestamptz | timestamptz
> ------------------------------+------------------------
> 1921-01-01 00:00:00+01:39:52 | 1922-01-01 00:00:00+02

FWIW, that is expected behavior if you're using the Europe/Helsinki time
zone data:

# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Europe/Helsinki 1:39:52 - LMT 1878 May 31
1:39:52 - HMT 1921 May # Helsinki Mean Time
2:00 Finland EE%sT 1981 Mar 29 2:00
2:00 EU EE%sT

Quite a lot of places were observing local mean time up to the early
1900s, so you'll see very strange GMT offsets for dates that far back.

regards, tom lane