Proposed 64-bit changes

Robbin Kawabata Robbin.Kawabata at
Fri Apr 29 20:59:58 UTC 2005

Some feedback -

1.  This is another idea for supporting dates into the far future.
Is it feasible for zic to encode variable information in the data file
for the last set of rules, that would be used for times past the last
entry in the transition table?  Then localtime() would use the variables
algorithmically rather than using table-driven data, for dates past the
last table entry.  Perhaps set a minimum size for the table entries
(ie, have table entries at least up to year xxxx.)

zic would effectively map the last set of transition rules of an Olson
timezone to an equivalent POSIX timezone.

2.  I'm not sure yet, but with 9x larger timezone binaries, Sun might
retain the old-style timezone binaries for timezone patch updates.
If so, it might be useful if zic has an option to produce old-style timezone

3.  POSIX timezone 64-bit time_t support
It seems the new localtime.c does not support 64-bit dates for POSIX
timezones.  Will this be supported?


> Date: Thu, 21 Apr 2005 15:24:10 -0400 (EDT)
> From: Arthur David Olson <olsona at>
> To: tz at
> Subject: Proposed 64-bit changes
> Below are diffs to the time zone code to cope with 64-bit time_t systems;
> these reflect suggestions I've received to date. Absent negative feedback,
> I'll update the ftp versions on May 2, 2005.

More information about the tz mailing list