Re: What's special about 1916-10-01 02:25:20? Odd jump in internal timestamptz representation

"Alistair Bayley" <alistair@abayley.org> writes:
> The first line of output puzzles me: why is '1916-10-01 02:25:20'
> 2627158159 seconds before 2000-01-01, while '1916-10-01 02:25:21' is
> 2627156080 before; a difference of 2080 seconds, or 34m:40s.

What timezone are you testing in?

Perusing the zic database makes me think it might be Europe/Dublin,
because there's a DST rule with a related breakpoint:

Zone    Europe/Dublin    -0:25:00 -    LMT    1880 Aug  2
            -0:25:21 -    DMT    1916 May 21 2:00
            -0:25:21 1:00    IST    1916 Oct  1 2:00s
             0:00    GB-Eire    %s    1921 Dec  6 # independence
             0:00    GB-Eire    GMT/IST    1940 Feb 25 2:00
             0:00    1:00    IST    1946 Oct  6 2:00
             0:00    -    GMT    1947 Mar 16 2:00
             0:00    1:00    IST    1947 Nov  2 2:00
             0:00    -    GMT    1948 Apr 18 2:00
             0:00    GB-Eire    GMT/IST    1968 Oct 27
             1:00    -    IST    1971 Oct 31 2:00u
             0:00    GB-Eire    GMT/IST    1996
             0:00    EU    GMT/IST

There's a whole raft of comments before that about where the zic people
got their info, so if you have doubts about this, take a look:
http://developer.postgresql.org/cvsweb.cgi/pgsql/src/timezone/data/europe

            regards, tom lane