Looking for the TZ command

[Jesper Norgaard Welen]

Thanks to Ken for this observation, the April-2-1945 timezone change in
Denmark does go into effect as can be easily checked with the below
commands

  $ TZ=Europe/Copenhagen date -d '1945-04-02 00:59:59 UTC'
  Mon Apr  2 01:59:59 CET 1945
  $ TZ=Europe/Copenhagen date -d '1945-04-02 01:00:00 UTC'
  Mon Apr  2 03:00:00 CEST 1945

However, as far as I know this can't be checked in Time Zone Converter
on the web http://www.timezoneconverter.com/cgi-bin/tzc.tzc nor in
Steffen Thorsen's page http://www.timeanddate.com/ because they both
enforce the official cutoff date of the TZ list in 1970. And I don't
think there are other web resources that use the TZ database which
enable conversions of timezones on dates before 1970.

I have tried to download Cygwin, compile the original tz code with
various C compilers
etc. but have not found a fool-proof way to get the above functionality
in Windows XP.
Maybe the tz list members can help on how to get it the easiest way,
given the OS
requirement?

Regards,
Jesper Nørgaard Welen

-----Original Message-----
From: Ken Pizzini [mailto:"tz."@explicate.org] 
Sent: Tuesday, April 26, 2005 19:42
To: Jesper Norgaard Welen
Cc: TZ-list
Subject: Re: TZ corrections


On Tue, Apr 26, 2005 at 06:56:31PM -0500, Jesper Norgaard Welen wrote:
> In my home country Denmark, it seems that there is a superfluous rule 
> for 2.nd of April 1945, which I suggest to delete:
> 
> Rule	Denmark	1940	only	-	May	15	 0:00	1:00
> S
> -Rule	Denmark	1945	only	-	Apr	 2	 2:00s	1:00
> S
> Rule	Denmark	1945	only	-	Aug	15	 2:00s	0
> -
> 
> Unles my interpretation is wrong, both before and after the rule takes

> effect in April 2, 1945, the time in Denmark would be GMT+2 (e.g. 
> GMT+1 +1), or does it mean that time is
> GMT+3?

The rule (in its broader context) says, before 02:00 on 1945-04-02,
Denmark was 1 hour ahead of GMT, but at 02:00 it went to being 2 hours
ahead.

> GMT+3? As a side-question, I haven't been able to check this with any
> Time Zone Converter (the web version has a cutoff date of 1970). Is 
> there any way to check this by a program, and which?

I used Gnu date to confirm the reading:
  $ TZ=Europe/Copenhagen date -d '1945-04-02 00:59:59 UTC'
  Mon Apr  2 01:59:59 CET 1945
  $ TZ=Europe/Copenhagen date -d '1945-04-02 01:00:00 UTC'
  Mon Apr  2 03:00:00 CEST 1945

		--Ken Pizzini