[time-nuts] Google NTP Servers and smearing leap seconds...

Doug Calvert dfc-list at douglasfcalvert.net
Thu Sep 15 20:34:39 UTC 2011

Time Technology and leaping seconds


"The solution we came up with came to be known as the “leap smear.” We
modified our internal NTP servers to gradually add a couple of
milliseconds to every update, varying over a time window before the
moment when the leap second actually happens. This meant that when it
became time to add an extra second at midnight, our clocks had already
taken this into account, by skewing the time over the course of the
day. All of our servers were then able to continue as normal with the
new year, blissfully unaware that a leap second had just occurred. We
plan to use this “leap smear” technique again in the future, when new
leap seconds are announced by the IERS."

More information about the time-nuts mailing list