GNU bug report logs - #11281
DST has not effect on windows XP when system DST adjustment is disabled

Previous Next

Full log

View this message in rfc822 format

From: help-debbugs <at> gnu.org (GNU bug Tracking System)
To: Stefan Kangas <stefan <at> marxist.se>
Cc: tracker <at> debbugs.gnu.org
Subject: bug#11281: closed (DST has not effect on windows XP when system
 DST adjustment is disabled)
Date: Fri, 07 Aug 2020 11:14:02 +0000

[Message part 1 (text/plain, inline)]

Your message dated Fri, 7 Aug 2020 04:12:57 -0700
with message-id <CADwFkmmS-kHqbfXVaFY4Xs=RhbTe-bSZ3Du_mBMq9Wgzd0CUiA <at> mail.gmail.com>
and subject line Re: bug#11281: DST has not effect on windows XP when system DST adjustment is disabled
has caused the debbugs.gnu.org bug report #11281,
regarding DST has not effect on windows XP when system DST adjustment is disabled
to be marked as done.

(If you believe you have received this mail in error, please contact
help-debbugs <at> gnu.org.)


-- 
11281: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=11281
GNU Bug Tracking System
Contact help-debbugs <at> gnu.org with problems

[Message part 2 (message/rfc822, inline)]

From: Shuguang Sun <shuguang <at> gmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: DST has not effect on windows XP when system DST adjustment is
	disabled
Date: Fri, 20 Apr 2012 00:35:40 +0800

I'm using GNU Emacs 24.0.95.1 (i386-mingw-nt5.1.2600) of 2012-04-02 on
MARVIN on WindowsXP SP3. I believe the issue exists in other version
as well.

In windows,
1. If I select the time zone GMP-5 EST (East Standard Time) and  check
the enable Daylight Saving Time checkbox, the command
display-time-world in emacs can show the time of New York correctly
with DST.
2. If I select the time zone GMP-5 EST (East Standard Time) and
UNCHECK the enable Daylight Saving Time checkbox, or if I select a
time zone without DST, the command display-time-world in emacs can not
show the time of New York correctly with DST.
But actually the display-time-world-list for New York is ("EST5EDT"
"New York"), which (EST5EDT) supposes to enable the Daylight Saving
Time to show the time.

I try the following code to trace the issue:
(setq old-tz (getenv "TZ"))
(setenv "TZ" "EST+5EDT")
(message (format "%s" (getenv "TZ")))
(message (format-time-string "%A %d %B %R %Z"))
(decode-time)
(setenv "TZ" "EST+5")
(message (format "%s" (getenv "TZ")))
(message (format-time-string "%A %d %B %R %Z"))
(decode-time)
(setenv "TZ" old-tz)

The output is (Because I select a timezone without DST in windows, the
time in the outputs is no DST as I described above):
"EST+5EDT"
"Thursday 19 April 11:27 EDT"
(26 27 11 19 4 2012 4 t -18000)

"EST+5"
"Thursday 19 April 11:27 EST"
(34 27 11 19 4 2012 4 nil -18000)

(DST is t if daylight saving time is in effect,otherwise nil.from the
doc of decode-time) From the output of decode-time, it is clear that
if the TZ is set to "EST+5EDT", the DST is effect. So it is most
likely the function format-time-string can not catch this information.
But it is still weird that it DOES has effect if I enable the DST in
the Windows system.

[Message part 3 (message/rfc822, inline)]

From: Stefan Kangas <stefan <at> marxist.se>
To: Shuguang Sun <shuguang <at> gmail.com>
Cc: 11281-done <at> debbugs.gnu.org
Subject: Re: bug#11281: DST has not effect on windows XP when system DST
 adjustment is disabled
Date: Fri, 7 Aug 2020 04:12:57 -0700

Stefan Kangas <stefan <at> marxist.se> writes:

> This was reported 7 years ago, but unfortunately never got a reply at
> the time.
>
> Is this still an issue on modern versions of Emacs?

More information was requested, but none was given within 39 weeks, so
I'm closing this bug.  If this is still an issue, please reply to this
email (use "Reply to all" in your email client) and we can reopen the
bug report.

Best regards,
Stefan Kangas

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.