A NOTE has been added to this issue. ====================================================================== https://austingroupbugs.net/view.php?id=1788 ====================================================================== Reported By: Guy Harris Assigned To: ====================================================================== Project: 1003.1(2016/18)/Issue7+TC2 Issue ID: 1788 Category: Base Definitions and Headers Type: Clarification Requested Severity: Comment Priority: normal Status: New Name: Guy Harris Organization: User Reference: Section: N/A Page Number: N/A Line Number: N/A Interp Status: --- Final Accepted Text: ====================================================================== Date Submitted: 2023-11-18 00:16 UTC Last Modified: 2024-01-08 17:50 UTC ====================================================================== Summary: The meaning of "Daylight Saving Time" should be clarified ====================================================================== Relationships ID Summary ---------------------------------------------------------------------- related to 0001253 clarify that "alternative time&quo... ======================================================================
---------------------------------------------------------------------- (0006617) geoffclare (manager) - 2024-01-08 17:50 https://austingroupbugs.net/view.php?id=1788#c6617 ---------------------------------------------------------------------- The discussions in teleconferences are leaning towards adding the definitions from RFC 8536 (as per https://austingroupbugs.net/view.php?id=1788#c6584), suitably adapted for POSIX. However, the question has also arisen of whether further changes should be made to acknowledge the limitation of the historical tzname[] and tm_isdst interfaces to cater for more than two timezone names. One suggestion is to mark the tzname[] array obsolescent (in Issue 8 TC1) and advise applications to obtain timezone names from either the tm_zone structure member or the strftime() %Z conversion instead. Another suggestion is that the standard could allow tzname[] to have more than 2 entries, but the question arose as to whether this is something that any implementation would want to do (or even has done already). Code from before the C standard used the tm_isdst returned by localtime() as an index for tzname[], and such code would "work" with more than two zone names. Later code is unlikely to have done this because the C standard said any positive tm_isdst value means DST is in effect (and thus in the context of POSIX, the zone name would be tzname[1]). So it is not clear how much benefit to applications there would be if an implementation were to make that change. The only thing stopping it at the moment is the definition as "extern char *tzname[2]" given on the tzset() page; the minimum change needed would be just to remove that "2". We would welcome any feedback on these suggestions. Issue History Date Modified Username Field Change ====================================================================== 2023-11-18 00:16 Guy Harris New Issue 2023-11-18 00:16 Guy Harris Name => Guy Harris 2023-11-18 00:16 Guy Harris Section => N/A 2023-11-18 00:16 Guy Harris Page Number => N/A 2023-11-18 00:16 Guy Harris Line Number => N/A 2023-11-20 01:03 Don Cragun Note Added: 0006573 2023-11-20 01:04 Don Cragun Relationship added related to 0001253 2023-11-20 17:10 kre Note Added: 0006576 2023-11-22 19:40 Guy Harris Note Added: 0006583 2023-11-22 20:12 Guy Harris Note Added: 0006584 2023-11-22 20:35 steffen Note Added: 0006585 2023-11-22 20:37 steffen Note Added: 0006586 2023-11-22 21:07 Guy Harris Note Added: 0006587 2023-11-23 23:19 steffen Note Added: 0006588 2023-11-23 23:21 steffen File Added: grep-over-bsds.txt 2023-11-24 02:46 Guy Harris Note Added: 0006589 2023-11-25 21:28 steffen Note Added: 0006590 2023-11-30 16:17 nick Relationship added parent of 0001779 2023-11-30 16:19 nick Relationship deleted parent of 0001779 2023-11-30 22:57 steffen Note Added: 0006594 2024-01-08 17:50 geoffclare Note Added: 0006617 ======================================================================
