Date: Tue, 30 Aug 94 10:41:01 -0400
From: dj AT ctron DOT com (DJ Delorie)
To: eliz AT is DOT elta DOT co DOT il
Cc: roe2 AT midway DOT uchicago DOT edu, djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: Why TZ=EST5EDT fails 

> that DST *might* be in effect.  It then either takes the DST offset
> from TZ, if it's there, or (in this case) assumes it's one hour less
> than standard offset.  If TZ doesn't contain a full Posix specification

Actually, there is NO assumption.  It looks up the posixrules zoneinfo
file to determine what "dst" means: how much of an offset it is, and
when to apply it.  If it can't load posixrules, the parse fails and
GMT0 takes affect.

I don't know if this is desirable behavior, but it's what actually
happens in ctime.c, which still matches the BSD sources in that part.