[time-nuts] June 30 2015 leap second

Hal Murray hmurray at megapathdsl.net
Sun Jan 11 19:35:05 EST 2015

martin.burnicki at burnicki.net said:
> So I think they smeared it over more than just a few minutes. I'd expect
> some hours, so standard NTP clients would just notify this as clock  drift
> (oscillator frequency offset) which they'd have to compensate.  Since ntpd's
> control loop is pretty slow it wouldn't respond quickly to  smears over a
> few seconds our hours. 

NTP and/or most kernels have a limit on how far they are willing to push the 
clock.  ntpd's limit is 500 ppm.  It's common for normal clocks to be off 100 
ppm, so you can't use all of that for leap-smearing.

If you assume that you can slew at 100 ppm, then it will take 10000 seconds 
to slew 1 second.  That's assuming a step function.  But Google uses cos to 
round off the corners, so the time will be longer.

These are my opinions.  I hate spam.

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