> I don't believe (but I've already been wrong once) that a programmer can > request a GMT or LT more than 4 months in the future.
I think you're right. An LT or GMT STIMER pops the next time that time of day occurs, so it can be at most 23:59:59.99 away (23:59:60.99 counting leap seconds). Hey, there's one for you, Gil. One June 30, could one have set an STIMER GMT of 23:59:60.hh? (I think I know the answer.) The interval processing has no good answer IMHO. Sure, it seems like 4 seconds after 23:59:58 on June 30 should be 00:00:01, not :02 -- but how far do you carry that? What is 30 days after 23:59:58? Would you expect it to be 23:59:57 on July 30? To be consistent, it should be. Can a prisoner serving a 30-year sentence demand to be released 'n' seconds early to account for the leap seconds of incarceration? How long is a day? Is it exactly 24 hours, or is it variable, depending on what day you are talking about? Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Paul Gilmartin Sent: Friday, July 03, 2015 2:24 PM To: [email protected] Subject: Re: Leap Second today! On Fri, 3 Jul 2015 15:33:37 -0500, George Kozakos wrote: >> >> So it actually waits for 4 seconds rather than the 3 requested. > >The problem is that at 17:59:59 when the STIMER is processed we don't >know that a leap second will occur at 18:00. > Actually, you could have known that for 4 months, ever since the IERS announced the leap second. (Less the time it takes for a PTF to be created, distributed, and installed.) I don't believe (but I've already been wrong once) that a programmer can request a GMT or LT more than 4 months in the future. So, when a leap second occurs, scan the timer queue. You have nothing better to do; user programs are nondispatchable. o If an entry is for an interval, leave it alone. o If an entry is for GMT or LT, add a second and replace in the queue in proper order. At a Daylight Saving Time boundary, scan the queue. o If an entry is for an interval or GMT, leave it alone. o If an entry is for LT, subtract an hour in the Spring (It may pop immediately). In the Fall, add an hour If it's in the ambiguous hour, it will not pop for another hour. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
