Summer to winter time

Systems management software
We are running 8 AS400's with Os400/V5.3. These machines run 24/7. At the end of this month, the clocks go back an hour to winter time. Is there a way that l can automate the clock setting (in-flight) without destroying the time-stamping on these machines or do l have to stop each AS400, wait one hour and then start each AS400 with the new time? Of course when we change to summer time we don't have this time-stamping problem, but if we can fully automate this l would be very grateful

Answer Wiki

Thanks. We'll let you know when a new response is added.

I have read on a french site that there is a new feature in V5R3 for hour tuning, in iseries navigator (my connexions / my400 / configuration).
it explains that you can work QTIMADJ, make a “smart” hour change (for example request 10 minutes to add 5 minutes), and more interesting, you can choose a hour object

ask your IBM representative about this new objects … and feed back us with your conclusion


Be aware that manipulating the system time may invalidate audit results and should <b>not</b> be done. Timestamps can be a legal element of transaction data.

Although it is inconvenient, the fact is that the local time does actually repeat. If you have manipulated your system time, then your timestamps are invalid and there is no (legal/audit) reason to maintain them in the first place — they are false. You might as well simply store a 64-bit sequence number or similar.

Don’t store time info in local time. Store it as UTC and convert to local time when it’s handled by a presentation layer. Otherwise, don’t process transactions during “repeat” hours.


Discuss This Question: 5  Replies

There was an error processing your information. Please try again later.
Thanks. We'll let you know when a new response is added.
Send me notifications when members answer or reply to this question.
  • Hypidia
    Hi, as far as I know there are serval ways to set the time automatic (e.g. NTP), but of course then you have twice the time from two to three o'clock, and of course this couses problems. For example all you scheduled job in between this hour run twice.
    0 pointsBadges:
  • Jangvej
    Have a look at the new system value qtimzon. I think this is what you are looking for.
    0 pointsBadges:
  • PaulThomas
    If you go to InfoCentre for V5R3 and navigate to....Systems Management....Time Management....What's New for will give you a quick overview on QTIMZON, SNTP, Time Adjustment, etc. You can then decide how you want to manage this change.
    0 pointsBadges:
  • ItDefPat1
    First: I haven't worked near an AS400 in ten years. Back then, I just worked interfaces and emulators on the PC side... BUT Have you considered a method of using GMT (might be called Universal time) for all time-stamps all the year? They all you would need is to add a location stamp (i.e. "US-NY (GMT-5)" that would effectively allow whoever reads to be able to authoritatively translate from the GMT time to local time. Of course, some AS400 guru is probably going to shoot about a thousand holes in this theory . . .
    15 pointsBadges:
  • Paul144hart
    As suggested, use GMT. You won't have the double hour problem. (Well humans might, but the computer won't)
    0 pointsBadges:

Forgot Password

No problem! Submit your e-mail address below. We'll send you an e-mail containing your password.

Your password has been sent to:

To follow this tag...

There was an error processing your information. Please try again later.

Thanks! We'll email you when relevant content is added and updated.


Share this item with your network: