Daylight Savings Time

Greg Woods woods at tmsoft.uucp
Wed Apr 5 03:56:30 AEST 1989


In article <1567 at lznv.ATT.COM> jlw at lznv.ATT.COM (J.L.WOOD) writes:
>In article <143 at dftsrv.gsfc.nasa.gov>, ken at inxt.uucp (Kenneth E. Stailey) writes:
>> As far as I understand it the UNIX(tm) PC is supposed to switch to daylight
>> savings time automatically.  I have NEVER seen it work right on time and
>> would like to know what's happening/how to fix it.
>> 
>> Currently I'm just munging /etc/TZ to simulate the effects of being in EDT.
>>
>[....]
>
>(1) In order to have the time zone change take place when the
>    UNIX-PC's algorithm says to change, you must have the machine
>    powered on and booted up at the time the change takes place -
>    ie at 2:00 am on the third Sunday morning  in April.  I leave
>    both my home and office UNIX-PCs running al the time.

All unix machines should ALWAYS be running, except during hardware
maintenance.  :-)

>(2) The Gov't in its infinite wisdom has changed the commencement
>    of DST to the first Sunday Morning in April.  I doubt that there
>    would be an official upgrade to fix this problem.  I've taken to
>    just changing the time and then changing it back again two weeks
>    later.

Likewise the Canadian Gov't, which didn't want to stray too far from
our Big Brother!

As a friend of mine is fond of saying: "That's nothing, what about all
those thousands of Japanese watches that automatically change two
weeks too late!"

As Ken originally suggested above, munging TZ is the best way to go if
you don't have source (or at least objects) for those utilities that
use the date functions.  Just set TZ=EDT4EST (in my case) for the two
weeks (in your (/etc/rc && /etc/profile) || /etc/TZ || /etc/TIMEZONE,
as the case may be) till the system catches up with our timely
politicians.  Changing the system time isn't as elegant.

Just for the record, I HATE daylight savings time, but then again, I'm
a farmer from Saskatchewan (right in the middle of a "natural"
timezone), so what do I know.  I must admit it does help a bit in Toronto.
-- 
						Greg A. Woods.

woods@{{tmsoft,utgpu,gate,ontmoh}.UUCP,utorgpu.BITNET,gpu.utcs.Toronto.EDU}
1-416-443-1734 [h]	1-416-595-5425 [w]		Toronto, Ontario, Canada



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