[ntp:questions] Lep seconds

Joseph Gwinn joegwinn at comcast.net
Fri Jan 4 03:10:29 UTC 2008

In article <T1199401837 at ex.djwhome.demon.co.uk.invalid>,
 david at ex.djwhome.demon.co.uk.invalid (David Woolley) wrote:

> In article <298286.52982.qm at web55415.mail.re4.yahoo.com>,
> marknmbox-88 at yahoo.com wrote:
> > compliant.  Is there a similar mod for NTP.  I am
> > hoping that there is a mod that will cause NTP to
> > supply theoretical UTC (even if it is not ascci).
> Both POSIX and NTP use UTC.  Your problem is that you are not using
> using UTC, but, rather, using TAI.

Actually, POSIX does *not* use UTC in the normal sense of the word, as 
no leap seconds are applied.

The fundamental POSIX timescale counts what amount to SI seconds from 
the POSIX Epoch, 0h 0m 0s UTC 1 January 1970.  Every day contains 
exactly 86,400 seconds.

That said, if one drives a POSIX box via NTP from a GPS timeserver set 
to emit UTC (versus GPS System Time), time on the POSIX box will be 
pretty close to UTC.

Joe Gwinn

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