"Clive D.W. Feather" wrote on 2005-01-20 12:34 UTC:
> >> A resolution was proposed to redefine UTC by replacing leap seconds by leap
> >> hours, effective at a specific date which I believe was something like 2020.
>
> I may be wrong here, but I thought the "leap hour" idea did *not* insert a
> discontinuity into UTC.
I think, the phrase "to redefine UTC by replacing leap seconds by leap
hours" can only mean going from
|UTC - UT1| < 1 s
to something like
|UTC - UT1| < 1 h
(or some other finite |UTC - UT1| bound like that).
That was certainly the idea of the BIPM proposal presented at the Torino
meeting.
> Rather, in 2600 (or whenever it is), all civil
> administrations would move their <local>-UTC offset forward by one hour,
> in many cases by failing to implement the summer-to-winter step back.
Such a proposal would be called "to redefine UTC by eliminating future
leaps" (i.e., by establishing a fixed offset between UTC and TAI). It
seems perfectly practical, at least as long as |UTC - UT1| < 24 h
(i.e., for the next 5000 years).
What local governments with regional civilian time zones do is outside
the influence of the ITU. But if leap seconds were eliminated from UTC
and a fixed TAI-UTC offset defined instead, then what you describe above
is indeed what I would expect to happen with most of them. Unless we
give up the notion of local time zones entirely, there would be a clear
need to keep them locked to UT1 + offset to within an hour or so.
Markus
--
Markus Kuhn, Computer Lab, Univ of Cambridge, GB
http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__
Received on Thu Jan 20 2005 - 05:40:16 PST