[Info-vax] Time change

[Bill Gunshannon]

In article <1c555380-f7e1-49e9-9773-1109df486756 at e24g2000vbe.googlegroups.com>,
	AEF <spamsink2001 at yahoo.com> writes:
> On Mar 9, 5:30 pm, "Richard B. Gilbert" <rgilber... at comcast.net>
> wrote:
>> Michael Moroney wrote:
>> > JF Mezei <jfmezei.spam... at vaxination.ca> writes:
>>
>> >> How is this implemented in alpha ? Does the system do a glorified
>> >> SYS$SETTIM to call a routine to execute at the next scheduled time
>> >> change ?  or is there some other type of mechanism that allows VMS to
>> >> schedule some event in the long term ?
>>
>> >> Also, if I have an alpha that was shutdown during this time, when it
>> >> next boots, will it automatically change its time ?
>>
>> > I had to deal with this during the last time change, to try to prevent
>> > the setback from happening automatically with software that really
>> > couldn't deal with it.
>>
>> > (the following is true only if SYSGEN AUTO_DLIGHT_SAV is set to 1, and
>> > things like NTP time synch aren't enabled. What's the setting on your
>> > VAX?)
>>
>> > The JOB_CONTROL process has a $SETIMR scheduled to expire at the time of
>> > the time change, and when it does, JOB_CONTROL sets the time according to
>> > the time zone rules.  It reads the info in when it starts up, and it has
>> > enough smarts to set the time right then if the time change happened when
>> > the system was down.
>>
>> > $ ANALYZE/SYSTEM
>> > SDA> SET PROCESS/IND=E   !JOB_CONTROL
>> > SDA> SHOW TQE
>> > Timer queue entries
>> > -------------------
>>
>> >   TQE                                                             PID/
>> > address                 Expiration Time                 Type    routine
>> > --------   -----------------------------------------   ------   --------
>> > ...
>> > 880EA380   00A93E1F.7B714530  1-NOV-2009 02:00:00.00   TSA---   0001000E   JOB_CONTROL
>> > SDA>
>>
>> > Next time change will take place Nov 1 at 2:00 AM.
>>
>> > You may notice that $SETIMR can schedule events to happen thousands of
>> > years in the future, if you can manage to keep your system up that long.
>>
>> > Aside: Were you guys in Canada supposed to change your time this last
>> > weekend?  The date of the time change was recently changed.
>>
>> It's politics as usual.  Changing the date of the time change is a
>> highly visible means for the politicians to show the people that they
>> are actually doing something!  ;-)
> Well, the recent fall-back change in the US was made because of the
> Halloween lobby. I don't know what moved the spring-ahead up, though.
> Might have to do with saving energy.

Yeah, that's what we keep hearing and it makes about as much sense as the
notion that Ben Franklin invented it to conserve candles.  I start my day
before the sun comes up and end my day after the sun goes down.  Where, in
that window, the real daylight appears has no effect on how much time I
spend using artificial lights.

bill

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>