[ntp:questions] Ruh, roh. Leap Second?

Martin Burnicki martin.burnicki at meinberg.de
Tue Jul 1 14:15:36 UTC 2008


Peter Laws wrote:
> 1 Time(s): Clock: inserting leap second 23:59:60 UTC
> RHEL 5.2 system running ntpq 4.2.2p1 at 1.1570-o Thu Jan 17 18:14:14 UTC 2008
> (1) which is the default for that distribution.  Grepping around in the
> logs it appears that most or all of my RHEL systems did it.
> I got this, too, on at least one system:
> Jun 30 19:34:53 ozz-1300 ntpd[2659]: time reset +1.000360 s
> Thing is, IERS, who I understand is in charge of these things, says:
> "There will NOT be a leap second introduced in UTC on 30 June 2008."
> (http://maia.usno.navy.mil/)
> So was that bogus?  A bug in RH's NTP code?  A problem with NTP itself?
> Operator error? :-)

Unless there is a bug in that specific version of ntpd you are running, ntpd
only propagates leap second announcements if it has received such an
announcement from either an upstream NTP server or reference clock, or from
a leap seconds file.

Which upstream servers are you using?

Are you using any local reference clock, e.g. a GPS receiver?

Your ntpd may also have received a faulty leap second announcement from an
upstream server which in turn has received the announcement from its time

For a short summary how leap seconds could/should be handled, see:

Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont

More information about the questions mailing list