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From: barmar@mit-eddie.UUCP (Barry Margolin)
Newsgroups: net.news,net.mail
Subject: Re: Timezones For Worldwide Networks
Message-ID: <4536@mit-eddie.UUCP>
Date: Sun, 23-Jun-85 02:06:44 EDT
Article-I.D.: mit-eddi.4536
Posted: Sun Jun 23 02:06:44 1985
Date-Received: Mon, 24-Jun-85 03:57:39 EDT
References: <143@kddlab.UUCP>
Reply-To: barmar@mit-eddie.UUCP (Barry Margolin)
Organization: MIT, Cambridge, MA
Lines: 37
Xref: watmath net.news:3473 net.mail:896

In article <143@kddlab.UUCP> asami@kddlab.UUCP (TOHRU ASAMI ) writes:
>I think we have to set up a program of timezones that can cover all of
>the world since it is very inconvenient to use GMT. How can you imagine
>someone has to type 1:00 am when it's morning!

Unfortunately, worldwide timezones contain a number of ambiguities.  For
instance, I believe IST is both Israel Standard Time and a time zone in
Germany whose expansion I don't recall at the moment.

The RFC-822 time format provides an escape for time zones not in the
standard list (as it is a US DOD standard, it only contains US time
zones and GMT): it defines a set of single-letter zone names, A-M
(skipping I) are the zones 1-12 hour west of GMT, N-Y are the zones east
of GMT, and Z, of course, is GMT (Zulu time).

>	{"aest", ZONE, -10 HRS},	/* Australian Eastern Time */
>	{"a.e.s.t.", ZONE, -10 HRS},
>	{"aesst", DAYZONE, -10 HRS},	/* Australian Eastern Summer Time */
>	{"a.e.s.s.t.", DAYZONE, -10 HRS},
>	{"acst", ZONE, -(9 HRS + HALFHR)},	/* Australian Central Time */
>	{"a.c.s.t.", ZONE, -(9 HRS + HALFHR)},
>	{"acsst", DAYZONE, -(9 HRS + HALFHR)},	/* Australian Central Summer */
>	{"a.c.s.s.t.", DAYZONE, -(9 HRS + HALFHR)},
>	{"awst", ZONE, -8 HRS},		/* Australian Western Time */
>	{"a.w.s.t.", ZONE, -8 HRS},	/* (no daylight time there, I'm told */
>
>This example also show the designer did not consider UNIX systems
>used outside the US, Europe, and Australia. 

And maybe he didn't get that right, either.  When we added Australian
time zones to Multics we got the names from our Australian users, and
they gave us EAST (Eastern Australian Summer (Standard?) Time, I think)
and a bunch of other zones that don't look anything like the above.
-- 
    Barry Margolin
    ARPA: barmar@MIT-Multics
    UUCP: ..!genrad!mit-eddie!barmar