On 1/10/24 15:05:23, Steve Summit via tz wrote:
Paul Gilmartin wrote:
Seconds since the epoch should not depend on TZ. The epoch is 0 UTC, not 0 local. . Right. So it seems to me that strftime should *not* support %s, or at least, not unless struct tm is expanded to include a field holding the original time_t value. . POSIX strftime(), which does nor include the proposed %s,: <https://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime.html#tag...> says:
"[CX] [Option Start] If a struct tm broken-down time structure is created by localtime() or localtime_r(), or modified by mktime(), and the value of TZ is subsequently modified, the results of the %Z and %z strftime() conversion specifiers are undefined, when strftime() is called with such a broken-down time structure." That is, it is the responsibility of the programmer to call strftime() with a TZ matching that corresponding to struct tm. I take this to mean that gmtime corresponds to GMT0. There is no need to ad a time_t value.
(But, yes, I saw Paul's earlier message mentioning the next POSIX draft talking about it.)
-- gil