Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!jarthur!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.unix.questions
Subject: Re: The switch to daylight savings time
Message-ID: <7289@auspex.auspex.com>
Date: 21 Apr 91 00:16:37 GMT
References: <1991Apr10.114836.10816@convex.com> <15842@smoke.brl.mil> <1991Apr17.151824.8236@robobar.co.uk>
Organization: Auspex Systems, Santa Clara
Lines: 39

>> I don't know about your system, but genuine UNIX handles such mappings
>> as DST entirely in user mode,
>
>What do you recommend regarding things like cron?

Well, I'm not sure what your question has to do with Doug's statement,
but:

>	a) run it in GMT
>	b) run it in local standard time, ignoring daylight.
>	c) run it in local time, restarting cron twice a year
>	d) teach cron to notice when someone's edited /etc/TIMEZONE
>	e) any others?

"cron" should run in whatever time zone your "crontab" entries are. 
E.g., if you have an entry starting with "30 19 * * *":

	if you want that entry to be run at 19:30 GMT, run "cron" in
	GMT;

	if you want it to be run at 19:30 local standard time, ignoring
	daylight, run it in local standard time, ignoring daylight;

	if you want it to be run at 19:30 local time, run it in local
	time.

If your system has a reasonable (i.e., Arthur Olson-style) time zone
implementation, if you run it in local time, you don't need to restart
it unless your government decides to muck with the daylight savings time
rules.

If your system isn't quite so reasonable, you may have to restart it at
other times.

>I opt for c) because uucp's crontab wants to run in the same timezone
>as British Telecom's charging algorithm (;-)  I'm not sure about d).
>Any good arguments for or against any or none of the above?

See above.