On 2017-12-10 22:16, Paul Eggert wrote:
Michael H Deckers via tz wrote:
The definition of the tm_isdst flag does not even mention standard time True, but other parts of POSIX make it clear that when tm_isdst is zero, standard time is intended. See: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_... and look at the TZ environment variable: POSIX says that its first few letters correspond to standard time and that later letters correspond to daylight saving time.
The meaning of fields in a POSIX TZ string does not define the meaning of the tm_isdst member of struct tm, which is only a matter of the C standard; POSIX cannot modify that meaning (they can only add extensions). Michael Deckers.