[LEAPSECS] Crunching Bulletin B numbers (POSIX time)

Steve Allen sla at ucolick.org
Tue Feb 22 18:19:22 EST 2011

On Tue 2011-02-22T18:01:00 -0500, Keith Winstein hath writ:

> If you just need GPS-CC time, you're right. Adding 19 seconds gets you

> within 1 microsecond of "TAI(USNO,MC)".

Correct me if I'm wrong, but I think if you

1) buy a Meinberg NTP server
2) configure it to emit GPS time instead of UTC
3) get the zoneinfo source code files
4) edit the "leapseconds" file and delete all leaps before 1980
5) compile the zoneinfo files yourself, asking for the "right" ones
6) install the resulting zoneinfo files
7) set the system to use the "right" timezone
8) set the system to use your Meinberg stratum 1 NTP server

then you have a system which is running its time_t based on GPS time,
therefore does not have issues with leap seconds resetting the clock,
and which produces a correct local time string for every time zone.

The trick being that you are not POSIX-compliant and cannot exchange a
time_t value with any POSIX-compliant system.

Steve Allen <sla at ucolick.org> WGS-84 (GPS)
UCO/Lick Observatory Natural Sciences II, Room 165 Lat +36.99855
University of California Voice: +1 831 459 3046 Lng -122.06015
Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m

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