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

"Alistair Bayley" <alistair(at)abayley(dot)org> writes:
> Actually, looking at the code again, I can see what happens, I think.
> This entry in win32_tzmap maps my GMT timezone to PG's Europe/Dublin
> timezone:
> {
> "GMT Standard Time", "GMT Daylight Time",
> "Europe/Dublin"
> }, /* (GMT) Greenwich Mean Time : Dublin,
> * Edinburgh, Lisbon, London */

Oh, you didn't say you were on Windows --- that changes things entirely.
That code doesn't try to probe the system behavior, it just has a
hardwired mapping.

Magnus, did you have a specific reason for choosing Europe/Dublin,
or was it just alphabetically first? Europe/London looks at least
marginally closer to what one would think "GMT" means:

Zone Europe/London -0:01:15 - LMT 1847 Dec 1
0:00 GB-Eire %s 1968 Oct 27
1:00 - BST 1971 Oct 31 2:00u
0:00 GB-Eire %s 1996
0:00 EU GMT/BST

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

regards, tom lane