timezones compatible with POSIX? [forwarded with permisison]

[Arthur David Olson]

> From peggyd at sco.COM Fri May  6 14:03:24 1994
> Return-Path: <peggyd at sco.COM>
> Received: from relay1.UU.NET by elsie.nci.nih.gov (4.1/SMI-4.1)
> 	id AA01798; Fri, 6 May 94 14:03:23 EDT
> Received: from sco.sco.COM by relay1.UU.NET with SMTP 
> 	(5.61/UUNET-internet-primary) id AAwotc03064; Fri, 6 May 94 14:03:19 -0400
> Received: from tehama.sco.COM by sco.sco.COM
> 	id aa08718; Wed, 6 May 70 11:08:32 PDT
> Received: from ping.sco.COM by tehama.sco.com id aa00201; 6 May 94 11:00 PDT
> From: mommy <peggyd at sco.COM>
> X-Mailer: SCO System V Mail (version 3.2)
> To: ado at elsie.nci.nih.gov
> Subject: timezones compatible with POSIX?
> Cc: peggyd at sco.COM
> Date: Fri, 6 May 94 10:59:55 PDT
> Message-Id:  <9405061059.aa21366 at ping.sco.com>
> Status: RO
> 
> 
> Hello,
> 
> I work at the Santa Cruz Operation, a company that makes
> UNIX.  I am designing and implementing the part of our
> installation that sets time zones.  A search for complete,
> thorough timezone information led me to your anonymous ftp
> site, and I would like to use the information that you make
> available, if possible.
> 
> However I am having some trouble reconciling the Rule
> format with the format we use, which is also the POSIX standard
> for timezone strings (as far as I can tell, looking at my
> POSIX doc).  The problem is in the area of shifting to and from
> Daylight Savings Time.  Our format is to use a Julian day,
> a month/week/day, or a week/day format.  It's different enough from
> your Rule format that timezones defined in your format (such as Sun >= 11)
> do not work in our format for more than a few years at best (is
> that the 2nd week of the month?  The 3rd week?  It shifts.)
> 
> I am wondering if anyone else has had this problem, and if you
> have seen any solutions?  Are there alternate ways of expressing
> timezones?  If you'd like more information I'd be happy to supply
> it.
> 
> Thanks very much for your help,
> 
> --peggyd at sco.com