Zdump for Warsaw 1944

Jesper Norgaard Welen jnorgard at prodigy.net.mx
Tue Mar 14 06:02:43 UTC 2006


I confirmed today at work on a Linux server that there is a problem
similar to Asia/Baku, for timezone Europe/Warsaw in 1944.

This is a fraction of the output produced for timezone Europe/Warsaw
using JodaTime:

UTC: 1944-04-03T00:59:59.000Z, Europe/Warsaw:
1944-04-03T01:59:59.000+01:00
UTC: 1944-04-03T01:00:00.000Z, Europe/Warsaw:
1944-04-03T03:00:00.000+02:00
UTC: 1944-09-30T21:59:59.000Z, Europe/Warsaw:
1944-09-30T23:59:59.000+02:00
UTC: 1944-09-30T22:00:00.000Z, Europe/Warsaw:
1944-09-30T23:00:00.000+01:00

The equivalent in zdump should be something like:

Europe/Warsaw  Mon Apr  3 00:59:59 1944 UTC = Mon Apr  3 01:59:59 1944
CET isdst=0
Europe/Warsaw  Mon Apr  3 01:00:00 1944 UTC = Mon Apr  3 03:00:00 1944
CEST isdst=1
Europe/Warsaw  Sat Sep 30 21:59:59 1944 UTC = Sat Sep 30 23:59:59 1944
CEST isdst=1
Europe/Warsaw  Sat Sep 30 22:00:00 1944 UTC = Sat Sep 30 23:00:00 1944
CET isdst=0

The error is the change from DST to standard time in 1944. It should
have been October 4.th. at 2:00 and not at the exact time that there is
a change rule from C-Eur to Poland, which *is* the October 1.st 1944 at
0:00, but this should not result in a change in GMT offset from +2 to
+1.

Here is the relevant lines from the tz database source, I'm suggesting
to add a line for DST for Poland rule before 1.st. October and copied a
line from the C-Eur rule for convenience, but there must be many ways to
do this:

Rule	C-Eur	1944	only	-	Apr	 3	 2:00s	1:00
S
# Whitman gives 1944 Oct 7; go with Shanks.
Rule	C-Eur	1944	only	-	Oct	 2	 2:00s	0
-

# Poland
# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE
LETTER/S
Rule	Poland	1918	1919	-	Sep	16	2:00s	0
-
Rule	Poland	1919	only	-	Apr	15	2:00s	1:00
S
+Rule	Poland	1944	only	-	Apr	 3	 2:00s	1:00
S
# Whitman gives 1944 Nov 30; go with Shanks.
Rule	Poland	1944	only	-	Oct	 4	2:00	0
-
# For 1944-1948 Whitman gives the previous day; go with Shanks.
Rule	Poland	1945	only	-	Apr	29	0:00	1:00
S
Rule	Poland	1945	only	-	Nov	 1	0:00	0
-

This should produce the following zdump output:

Europe/Warsaw  Mon Apr  3 00:59:59 1944 UTC = Mon Apr  3 01:59:59 1944
CET isdst=0
Europe/Warsaw  Mon Apr  3 01:00:00 1944 UTC = Mon Apr  3 03:00:00 1944
CEST isdst=1
Europe/Warsaw  Tue Oct  3 23:59:59 1944 UTC = Wed Oct  4 01:59:59 1944
CEST isdst=1
Europe/Warsaw  Wed Oct  4 00:00:00 1944 UTC = Wed Oct  4 01:00:00 1944
CET isdst=0

Jesper Nørgaard Welen
Email: jnorgard at Prodigy.Net.mx	
Project Leader (Líder de Proyecto) Software
CIMMYT  -  Centro Internacional de Mejoramiento de Maíz y Trigo
Dirección: CIMMYT Int. c/o Jesper Nørgaard
Km. 45, Carretera México-Veracruz
El Batán
Texcoco, Edo. de México
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Fax:	+52 (55) 58-04-75-58
Tel. Casa:   53-10-05-95  ó  53-10-97-78
Download the free program World Time Explorer, I made:
http://www.worldtimeexplorer.com/index.html



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