bug#13982: 24.2; Bug in function format-time-string when used under Windows

[Bostjan Vilfan <bjvilfan@gmail.com>]

On Tue, Mar 19, 2013 at 7:02 PM, Eli Zaretskii <eliz@gnu.org> wrote:
>> Date: Tue, 19 Mar 2013 12:56:30 +0200
>> From: Bostjan Vilfan <bjvilfan@gmail.com>
>> Cc: 13982@debbugs.gnu.org
>>
>> Hello, and thanks for your message. I did as per your instructions,
>> and the value of
>>
>>  (format-time-string "%H:%M %z %Z")
>>
>> is "12:30 +0200 CDT" (actual local time was 11:30; so in other words
>> emacs thinks local time is 1 hour ahead of actual local time)
>>
>> Your remark that all your Windows machines give the correct answer
>> indicates that there must be some settings on my computer that is at
>> fault; but I have no idea what that is.
>
> I don't think there's a Windows time zone whose name is "CDT".  Can
> you check if you happen to have a TZ variable in the environment, and
> if so, what's its value?  Please look both in the Computer's
> Properties and in the command shell from which you invoke "emacs -Q".
>
TZ=CET-1CDT,3,-1,0,7200,10,-1,0,10800,3600

the reason I need TZ is that I still use the (quite old) RCS software.
Up to now I did not encounter any problems with TZ. With regard to
"CDT", I may have improvised a bit with the daylight savings name for
my timezone.

> Also, I asked you to tell which time zone do you see in the Date/Time
> dialog of your Windows system.  Right-click on the time display in the
> right corner of your task bar, and select "Adjust date/time".  In the
> dialog that pops, click "Change timezone", and tell the name of your
> current Windows time zone that is shown in the middle of the dialog.
>
> If the Windows time zone and the time zone given to Emacs are
> different, you can have all kinds of "1 hour off" problems, especially
> around daylight savings change date.
>
there is no abbreviation, just the following:

(UTC+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna

>> I made one additional experiment: the version of emacs I was using was
>> a modification by Vincent Goulet
>> (http://vgoulet.act.ulaval.ca/en/emacs/). I thought that in some way
>> that version made some hidden changes, so I completely uninstalled it,
>> and installed the version obtainable from the GNU site. The result of
>> evaluating the above form was the same.
>
> Which leaves your system as the prime suspect.

Hello,
I hope I answered your specific questions above. There is one item
that comes to mind, though, which I don't know whether it is evident
in the data in my original error report, namely, that my system is
64-bit Windows 7. I also have a 32-bit Windows 7 installation, but
currently I am unable to access it. As soon as I will be able to do
so, I will check how emacs behaves there.
Regards,
Bostjan