[ntp:questions] basic questions about the leapsecond

Chris Adams cmadams at hiwaay.net
Tue Dec 16 02:40:25 UTC 2008


Once upon a time, Unruh  <unruh-spam at physics.ubc.ca> said:
>Ie, it would seem that if you are getting your time from the Garmin GPS, at
>midnight on Dec 31, ntp will suddenly find that it is out by one second.
>Since that is longer than 128ms, it will jump the time by resetting the
>system clock by a second  the next time it queries the GPS receiver
>input ( somewhere
>between 16 and 1000 seconds later, depending on the poll interval for the
>GPS receiver.)
>
>Ie, for a while your system time will be out by a second. 

If you have both a NMEA GPS unit (AFAIK there's no NMEA sentence to
alert for pending leap seconds, and even if there is, there doesn't
appear to be support for such in ntpd) and NTP servers specified (that
do set the leap second flag in advance), will ntpd learn about the leap
second from the other servers and use it (even though the GPS/PPS unit
is the "system peer")?

-- 
Chris Adams <cmadams at hiwaay.net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.




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