In a previous email Robbin Kawabata has
shown unintended changes for
the tz database relating to the change for the C-Eur Rule in
2008d. Here are the relevant
portions of the tz database together with
a few suggestions to
mend it (with + and - as the first letter of the
relevant lines):
Rule C-Eur 1944 1945 - Apr Mon>=1
2:00s 1:00 S
# Whitman gives 1944 Oct 7; go with Shanks &
Pottenger.
Rule C-Eur 1944 only - Oct 2
2:00s 0 -
Rule C-Eur 1945 only - Sep 16
2:00 0 -
...
# These are for backward compatibility with older
versions.
...
#
Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone WET 0:00 EU WE%sT
Zone CET 1:00 C-Eur CE%sT
Zone MET 1:00 C-Eur ME%sT
...
Zone Europe/Sofia 1:33:16
- LMT 1880
1:56:56 - IMT 1894 Nov
30 # Istanbul MT?
2:00 - EET 1942 Nov
2 3 :00
- 1:00 C-Eur CE%sT 1945
Apr 2
3:00
+ 1:00 C-Eur CE%sT 1945
+ 1:00 - CET 1945
Apr 2 3:00
2:00 - EET 1979 Mar
31 23:00
...
Zone Europe/Budapest 1:16:20 - LMT 1890
Oct
1:00 C-Eur CE%sT 1918
1:00 Hungary CE%sT 1941
Apr 6
2:00
- 1:00 C-Eur CE%sT 1945 May 1
23:00
+ 1:00 C-Eur CE%sT 1945
1:00 Hungary CE%sT 1980
Sep 28
2:00s
...
Zone Europe/Belgrade 1:22:00 - LMT 1884
1:00 - CET 1941
Apr 18 23:00
- 1:00 C-Eur CE%sT 1945
May 8
2:00s
+ 1:00 C-Eur CE%sT 1945
+ 1:00 - CET 1945
May 8 2:00s
1:00 1:00 CEST 1945
Sep 16 2:00s
The problem arose because the C-Eur rules had no
DST for 1945, making other
timezones free to use it without effects for 1945.
However this meant that
Zone CET and Zone MET did not have DST for 1945,
which is not very adequate.
I agree with the action of adding DST for C-Eur
for 1945, but that means that
other timezones using C-Eur must be changed to
return status quo.
As far as I can see only Europe/Sofia,
Europe/Budapest and Europe/Belgrade are
affected, though of course
Europe/Skopje and other timezones linking to
Europe/Belgrade will be equally
affected.
My suggestion for Europe/Sofia and Europe/Belgrade
are to stop using C-Eur from
1945 since the timezone abbreviation (CET) will
be the same, and then only start
CEST from the previous cutoff
dates.
For Europe/Budapest the answer is easier since
Hungary rule already has the
DST start time of May 1, 1945 at 23:00 encoded,
so the Hungary rule can simply
be used insted of C-Eur since
1945.
I don't have access
to a zic compiler to see if the desired results crop out, so I
will leave that to
people who can check it.
Jesper Nørgaard Welen
Email:
jnorgard@Prodigy.Net.mx
Project Leader (Líder de Proyecto)
Software
CIMMYT - Centro Internacional de Mejoramiento de Maíz y
Trigo
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