With the latest time zone code I tried `zdump -v right/US/Pacific' and got the following output. This looks wrong to me -- the times labeled `GMT' are actually International Atomic Time (TAI), not Coordinated Universal Time (UTC). zdump uses gmtime to print the GMT part. But even with leap second support, gmtime should yield UTC, not TAI, at least according to ANSI C X3.159-1989 section 4.12.3.3. Or am I missing something here? right/US/Pacific Sun Apr 4 10:00:16 1993 GMT = Sun Apr 4 01:59:59 1993 PST isdst=0 right/US/Pacific Sun Apr 4 10:00:17 1993 GMT = Sun Apr 4 03:00:00 1993 PDT isdst=1 right/US/Pacific Thu Jul 1 00:00:17 1993 GMT = Wed Jun 30 16:59:60 1993 PDT isdst=1 right/US/Pacific Thu Jul 1 00:00:18 1993 GMT = Wed Jun 30 17:00:00 1993 PDT isdst=1 right/US/Pacific Sun Oct 31 09:00:17 1993 GMT = Sun Oct 31 01:59:59 1993 PDT isdst=1 right/US/Pacific Sun Oct 31 09:00:18 1993 GMT = Sun Oct 31 01:00:00 1993 PST isdst=0