[LEAPSECS] POSIX? (was Time math libraries, UTC to TAI)

[Steve Allen]

On Fri 2016-12-30T17:59:14 -0700, Warner Losh hath writ:
> if you were to transition to a TAI world, then you'd not be able to
> implement the latter for a TAI time of the UTC time at some
> Y/M/D/H/M/S past the end of the next six month boundary, since it is
> impossible to have that knowledge.

This is a well-known problem in the arena of calendaring applications
when an event is to be attended by parties in many timezones.  The
calendaring applications must be able to recognize that the timezone
rules for one or more of those attending can change (sometimes with
much less notice than the 6 months for leap seconds) between the
scheduling and the event.  This requires that the event be stored with
a home time zone (in addition to the time in that zone) in which its
time is fixed, and that everyone else can be alerted if the local
authorities announce that home time zone or their own time zone is
being changed.

--
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