[ntp:questions] Leap second question

Chuck Swiger cswiger at mac.com
Wed Mar 20 17:18:06 UTC 2013


Hi--

On Mar 19, 2013, at 6:15 PM, Stephen Yu wrote:
> The question is why "sys_leap = LEAP_ADDSECOND" is unconditional. Is this based on the prior knowledge that earth always rotates slower? In other word, could it ever be "sys_leap = LEAP_DELSECOND"?

Over the long term, the earth's rotation is slowing over time primarily due to tidal friction from the moon.  It's possible for a large-scale event like a big earthquake or meteor strike to increase the earth's rotational speed slightly, but even a ~9.0 richter earthquake resulted in a speedup of only a few milliseconds.

Regards,
-- 
-Chuck



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