Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!sgi!vjs@rhyolite.SGI.COM
From: vjs@rhyolite.SGI.COM (Vernon Schryver)
Newsgroups: comp.sys.sgi
Subject: Re: EDT settings on 3xxx series
Summary: set TZ
Message-ID: <29974@sgi.SGI.COM>
Date: 4 Apr 89 18:01:51 GMT
References: <8904041707.AA02529@aero4.larc.nasa.gov>
Sender: daemon@sgi.SGI.COM
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 36


The timezone is not wired into any IRIS kernel.  It may be in some others,
but all IRIS's all run flavors of System V.  (Forget the V-kernel, and the
old 4.2 experiments you may have heard of.)  Remember that in SV, ctime(3)
uses the TZ environment variable (or TIMEZONE in SVR3) to know how to
convert from the GMT maintained in the kernel to whatever you want to see.

To fix time on an IRIS 3000 running 3.6, you can:

1) change the date on your machine.  You will confuse your uucp and sendmail
	neighbors, but if you are not running timed(1m), nntp, timeslave(1m)
	et al, this is probably simplest.  You will have to ignore the
	'[ECMP]ST' in date strings.  You will also have to change the date
	again in a few weeks.  If you use NFS and make(1) for software
	development, simply changing the date will cause some little 
	confusion, unless all machine change it similarly.

	To everyone inside SGI:  DO NOT DO THIS, USE #2, #3, or #4 BELOW!

2) save and edit /etc/TZ, and reboot.  For example, the string 'PDT7'
	solves the symptom on the west coast.  You will need to remember
	to restore the old contents of /etc/TZ after May 1, and before
	fall.  You must reboot to get everything using the new envirnment
	variable.

3) don't worry, be happy, and use a real clock for the rest of the month.
	This is probably the best "solution."

4) get rid of this "day light savings" silliness, and use UTC/GMT.
	You will be able to babble 'zulu' and other impressive
	things.


Vernon Schryver
Silicon Graphics
vjs@sgi.com