[ntp:questions] Leap second to be introduced in June

Mike S mikes at flatsurface.com
Sun Jan 18 22:13:21 UTC 2015

On 1/13/2015 11:46 PM, William Unruh wrote:

> That is a translation from seconds to ymdhms. The problem is not there.
> it is in the UTC seconds.
> In UTC one second disappears after the leap second, but not before or
> during. Thus UTC seconds numbering is simply disconinuous (jumps back) .

UTC jumps neither forward nor backwards. UTC simply allows minutes of 
59, 60 or 61 seconds. There is NO discontinuity. The canonical form of 
UTC (and TAI) is ymdhms.

TF.460 describes very clearly how UTC is enumerated. "A positive 
leap-second begins at 23h 59m 60s and ends at 0h 0m 0s of the first day 
of the following month. In the case of a negative leap-second, 23h 59m 
58s will be followed one second later by 0h 0m 0s of the first day of 
the following month"


The issue you're describing is an issue with POSIX time, which doesn't 
handle leap seconds.

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