[ntp:questions] Leap second to be introduced in June
Harlan Stenn
stenn at ntp.org
Fri Jan 23 04:42:59 UTC 2015
Mike S writes:
> Both TAI and UTC are continuous, and could in a non-standard way, be
> represented by real numbers ("Time," below), where they wouldn't differ.
> TAI and UTC only differ in how they're "labelled," as you say. It's
> POSIX which isn't monotonic or continuous, it repeats leap seconds. How
> they handle leap seconds:
>
> Time UTC TAI POSIX
> n+0 23:59:58 00:00:33 n+0
> n+1 23:59:59 00:00:34 n+1
> n+2 23:59:60 00:00:35 n+2
> n+2.9 23:59:60.9 00:00:35.9 n+2.9
> n+3 00:00:00 00:00:36 n+2
> n+3.9 00:00:00.9 00:00:36.9 n+2.9
> n+4 00:00:01 00:00:37 n+3
The only problem with this approach is that with this approach under
POSIX, time is discontiguous - one cannot cleanly map from POSIX to UTC
or TAI.
This is some of the fun stuff NTF"s General Timestamp API gets to deal
with.
--
Harlan Stenn <stenn at ntp.org>
http://networktimefoundation.org - be a member!
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