On Sat, 25 Oct 2025 11:39:05 -0500, Paul Gilmartin <[email protected]> wrote:
>IANA solution does solve the time "change" problem. Even in the Unix world this is not always true. For instance, repeating events in a calendar where global participants are not sharing the event and have their own unique event. You don't get a warning about time changes For z/OS system products, IANA is irrelevant. z/OS, CICS and ??? allow for 1 local timezone and planning for time change may be needed. Certainly the impact is far less at 2:00am Sunday than during the 2:00pm on Thursday but the possibility exists. For applications, IANA is a tool but not the complete answer (e.g. repeating events in calendar). Dealing with time changes and time zones is something every application must consider despite IANA. IANA is extremely useful but it is not a complete solution. >WTF‽ I know no processor, "so much slower where an hour time change goes >unnoticed." z/OS with it's huge compute power, is mostly centralized. Linux, with it's slow compute power is often decentralized and used by local staff. Either people don't notice the problem or have learned to live with it. > Nothing changes, neither system control blocks nor code. > at 02:00 on that Sunday morning. Clearly you don't understand the complexity of time change and the system. For instance, job abc must start at 2:00am to guarantee is completes by 6:00am. Does the job scheduler start it at 1:00am or do you accept that the job completes after 6:00am. Just because you don't understand the problem doesn't mean the problem does not exist. >a system clock value and a timezone yields identical result for identical >input regardless >when it is called. Sunday 4:00am minus 1:00am can be 2, 3 or 4 hours if using local time to calculate. >z/OS should awaken to this fact, well known everywhere else in the IT world, ROTFLOL, the rest of the world has a single environment (processes and threads). z/OS does not have a single environment (CICS, IMS, TSO, batch and more). Implementing localtime in z/OS has never been a priority. Customers needing this have written their own implementation. Simply put, local time is not a priority because customers can easily implement their own solutions which could include IANA. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
