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March 08, 2019

It may be later than you think, by Monday

Clock-face
Daylight Saving Time kicks off early on Sunday. By the time you're at work on Monday it might seem late for the amount of light coming in your window. If you're working at home and next to the window, it will amount to the same thing. We lose an hour this weekend.

This reset of our circadian rhythms isn't as automatic as in later-model devices. Like my new Chevy, which is so connected it changes its own clocks, based on its contact with the outer world. HP 3000s and MPE systems like those from Stromasys don't reach out like that on their own. The twice-a-year event demands that HP 3000 owners adjust their system clocks.

Programs can slowly change the 3000's clocks in March and November. You can get a good start with this article by John Burke from our net.digest archives.

The longer that MPE servers stay in on the job, the more their important date manipulations will be to its users. The server already hosts a lot of the longest-lived data in the industry. Not every platform in the business world is so well-tooled to accept changes in time. The AS/400s running older versions of OS400 struggled with this task.

You also need to be sure your 3000's timezone is set correctly. Shawn Gordon explained how his scheduled job takes care of that:

"You only have to change TIMEZONE. For SUNDAY in my job scheduler I have the following set up to automatically handle it:

IF HPMONTH = 3 AND HPDATE > [this year's DST] THEN
   ECHO We are going back to Standard Time
   SETCLOCK TIMEZONE = W8:00
ENDIF
IF HPMONTH = 11 AND HPDATE < [this year's ST] THEN
   ECHO Setting clock for Daylight Savings Time
   SETCLOCK TIMEZONE = W7:00
ENDIF

3000 customers say that HP's help text for SETCLOCK can be confusing:

SETCLOCK  {DATE= date spec; TIME= time spec [;GRADUAL | ;NOW]}
   {CORRECTION= correction spec [;GRADUAL | ;NOW]}
   {TIMEZONE= time zone spec}
   {;CANCEL}

Orbit Software's pocket guide for MPE/iX explains shows the correct syntax. In this case, ;GRADUAL and ;NOW may only be applied as modifiers to the DATE=; TIME= keywords, not to ;CORRECTION=.

09:47 PM in Hidden Value, Homesteading | Permalink

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