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From: std-unix@ut-sally.UUCP (Moderator, John Quarterman)
Newsgroups: mod.std.unix
Subject: Re: RFC.001 Timezone Interface
Message-ID: <5382@ut-sally.UUCP>
Date: Mon, 21-Jul-86 09:46:02 EDT
Article-I.D.: ut-sally.5382
Posted: Mon Jul 21 09:46:02 1986
Date-Received: Mon, 21-Jul-86 21:02:14 EDT
Organization: IEEE 1003 Portable Operating System for Computer Environments Committee
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Approved: jsq@sally.UUCP
In-Reply-To: <5369@ut-sally.UUCP>

Date: Mon, 21 Jul 86 01:23:29 edt
From: im4u!caip!mark@cbosgd.ATT.COM (Mark Horton)
Organization: AT&T Bell Laboratories, Columbus

>System V also defines external variables for the current timezone and daylight
>savings rule.  Are there any programs that actually use these?  Should they be
>part of the interface as well?  (Or some equivalent functionality?)

Yes, there's an important use.  If you're generating an RFC 822 compatible
>Date: line, you need to know the local offset from GMT or the time zone
name.  You can't just plug in the time zone name, because only the names
in the USA are allowed by 822, and if you try to extend that to the rest
of the world, you run into ambiguities.  In general, you can't assume that
someone in an arbitrary location in the world will understand your local
name for your time zone.  So you have to generate a zone like "+hhmm".

One might even claim that, in a zone like Japan, asking for the time zone
name should return "+0900" rather than "JST".  Probably not, but it's
a thought.

	Mark

Volume-Number: Volume 6, Number 35