On Thu, 15 Aug 2019 16:56:32 -0400, Thomas David Rivers wrote: > ... >The Dignus runtime main() start-up from a BATCH or TSO start examines the CVTTZ >value and constructs a TZ that offers the proper offset from UTC (again,this >assumes >the machine's clock is set to UTC and that CVTTZ is properly set.) This >basically > According to the PoOp, the proper setting for the machine clock is not UTC but TAI minus 10 seconds. Sometimes a half-minute (and growing) matters.
What happens if that startup and the program's STCK straddle a Daylight Saving boundary? >gives you a "local time" for the machine, the user would need to set TZ to >something >else if they are not in the same locality as the machine. Under a USS >start-up, we >inherit the TZ environment variable from the BPX environment. > >Thus - the entire question about "what time is it" is totally answered when you >can reliably answer the question of "where are you?" > Which can be complicated. Arizona, sort of within Mountain time, does not observe DST. The Navajo Nation, mostly within AZ observes DST. The Hopi Reservation, an enclave entirely surrounded by the Navajo Nation follows the AZ convention. Things are worse for the Autonomous Republic of Crimea. IBM really ought to: o Provide initialization of TZ in all cases. o Provide a single point of control for /etc/rc, /etc/init.options, CVTTZ, and CVTLDTO so they don't get out of sync because of careless sysadmins. IBM doesn't care. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
