On Fri, 14 Sep 2018 09:14:25 -0700, Charles Mills wrote:
>I believe that is in fact in the standard.
>
The best I easily find is:
https://www.iers.org/IERS/EN/Science/EarthRotation/UTC.html
...
UTC is defined by the CCIR Recommendation 460-4 (1986). It differs from
TAI by an integer number of seconds, in such a way that UT1-UTC stays
smaller than 0.9s in absolute value. The decision to introduce a leap second
in UTC to meet this condition is the responsibility of IERS (Bulletin C).
According to the CCIR Recommendation, first preference is given to the
opportunities at the end of December and June, and second preference to
those at the end of March and September. Since the system was introduced
in 1972 only dates in June and December have been used.
I don't see any mention of more than 12 leap seconds within a year. I'd rather
expect up to every month, then half-month, then daily, then hourly. A 62-second
minute would be a desperate last resort.
The ANSI C standard generously, or probably naively allows 62-second minutes.
UTC1-UTC grows quadratically so it'll happen sooner than you expect.
https://en.wikipedia.org/wiki/%CE%94T
(I guess that's a parabola.)
>-----Original Message-----
>From: Mike Schwab
>Sent: Friday, September 14, 2018 7:37 AM
>>
>> ... The UTC specification deals with that by requiring the value
>> 23:59:60.xxx during a leap second. The sequence of events is
>> well-determined.
>
>So, after a few thousand years and all days have 23:59:60 we will
>start having leap days lasting until 23:59:61?
-- gil
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