Re: Time Change

On 16-Feb-2012 08:59 , Jerry C. Adams wrote:

We're on V5R1 here (with no near term hopes of upgrading hardware or
OS) so the change to DST doesn't happen automagically for us.

In the Fall, I just changed the System vale QTIME early Sunday
(we're not 24x7 by any stretch of the imagination) so no user job
was impacted. But Spring may be a different issue.

Anyway, I was reading Bruce, et als, "APIs At Work" tome and came
across the QWCADJTM api. I was wondering if anyone had used (or are
still using) this api to adjust the system clock for System i's when
on old releases (such as ours) that can't/.won't do it? If so, how
did it work out for you?

The most negative impacts IMO, would be seen when the time is moved backwards, due to [actual and potential] impacts to the OS and related features, irrespective of the presence of "user jobs"; i.e. journaling or any other date\time specific activity persist without the presence of any user jobs. However moving the time forward has almost no direct impact similarly, because that is the natural direction of time; e.g. if some code subtracts the present time from a future time, then all is good, but if that code subtracts a present time from a future time where that 'future' time [which is assumed to always be in the future, since that is how the future is represented by time] is in fact a time in the past due to moving the clock backwards, then all is not well because the difference in time is negative [and time differences are expected to be unsigned numeric].

Not sure what you would want to do with the noted API, since according to the documentation, the Adjust Time (QWCADJTM) "API introduced: V5R3"
http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/apis/qwcadjtm.htm

Regards, Chuck