[tz] Leap seconds puzzle

Alan Barrett apb at cequrux.com
Wed Apr 8 21:44:24 UTC 2015

On Wed, 08 Apr 2015, Paul_Koning at dell.com wrote:
> So here is the puzzle.  I would expect WWV, and www.time.gov, 
> to reflect leap seconds.  So why would they give me a time that 
> matches, to the second, the POSIX time on my workstation?  Does 
> NTP send POSIX seconds since epoch rather than real ones?

If you represent time as an number of seconds since some epoch, 
then whether or not leap seconds are counted makes a difference to 
the integer part of the value.

If you express time as year/month/day/hour/minute/second, then 
(provided you follow UTC), observers can't really tell whether or 
not leap seconds are counted, unless they watch really closely 
around the time of a leap second transition.

--apb (Alan Barrett)

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