nanog mailing list archives

Re: REMINDER: LEAP SECOND


From: Philip Homburg <pch-nanog () u-1 phicoh com>
Date: Wed, 24 Jun 2015 15:34:53 +0200

In your letter dated Wed, 24 Jun 2015 14:05:34 +0100 you wrote:
Philip Homburg <pch-nanog () u-1 phicoh com> wrote:

For UTC the analog approach would be to keep time in TAI internally and
convert to UTC when required.

This is much less of a solution than you might hope, because most APIs,
protocols, and data formats require UT. (Usually not UTC but a
representation isomorphic to traditional UT which ignores leap seconds.)

Supporting legacy formats can be annoying. In some cases it would be no
problem. For example NTP. If there is a defined way to convert between TAI
and UTC then converting TAI to NTP timestamps is easy except during an
actual leap second. Which is not really a problem.

Unix systems would probably need a few new system calls to accept time in TAI.

File formats like tar are unlikely to matter much: find a consistent way of
encoding time around the leap second and most likely nobody will care.

In any case, it would be nice if future formats and systems could have a 
sensible time keeping system. 



Current thread: