[LEAPSECS] Crunching Bulletin B numbers (POSIX time)

[Paul Sheer]

You don't need to buy anything.

You could hack regular NTP to do the same thing.


It just needs to remove the leap second bit and accumulate 1 second
every time it sees the bit coming from the upstream server.


In actual fact we need BOTH timescales for backward compatability....
i.e. to have a migration path to this new correct timescales.

-paul


On Tue, 2011-02-22 at 15:19 -0800, Steve Allen wrote:

> 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)

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