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From: urban@cbnewsl.att.com (john.urban)
Newsgroups: comp.unix.questions
Subject: Re: The switch to daylight savings time
Message-ID: <1991Apr19.150832.27252@cbnewsl.att.com>
Date: 19 Apr 91 15:08:32 GMT
References: <1991Apr10.114836.10816@convex.com> <15842@smoke.brl.mil> <1991Apr17.151824.8236@robobar.co.uk>
Distribution: na
Organization: AT&T Bell Laboratories
Lines: 29

In article <1991Apr17.151824.8236@robobar.co.uk> ronald@robobar.co.uk (Ronald S H Khoo) writes:
>gwyn@smoke.brl.mil (Doug Gwyn) writes:
>
>> 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?
>
>	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?
>
>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?
>-- 
>Ronald Khoo <ronald@robobar.co.uk> +44 81 991 1142 (O) +44 71 229 7741 (H)

I vote for semi-d.  Teach cron to notice when the change from Standard Time
to Daylight Time occurs (or visa versa) and adjust cron's internal time so that
jobs running at 23:45 (e.g. uucp's nightly jobs) continue to run at 23:45 and
not 00:45 or 22:45 after the switch.  NOTE: things will straight out once
date XXX (where XXX is the current time) is run.

Sincerely,

John Ben Urban