Ed Davies wrote:
Still, it's a strange assumption, given that TF.640 allows, I
understand, leaps at the end of any month. Unofficially, the
wording seems to be:
A positive or negative leap-second should be the last second
of a UTC month, but first preference should be given to the end
of December and June, and second preference to the end of March
and September.
Anybody got access to a proper copy and can say whether that's
right or not? If it is right then the Wikipedia article on leap
seconds needs fixing.
The text you quoted is taken exactly fromITU-R Recommendation TF.640-4,
Annex I ("Time Scales"), paragraph D ("DUT1"), sub-paragraph 2
("Leap-seconds"):
2.1 A positive or negative leap-second should be the last second of
a UTC month, but first preference should be given to the end of
December and June, and second preference to the end of March
and September.
2.2 A positive leap-second begins at 23h 59m 60s and ends at 0h 0m 0s
of the first day of the following month. In the case of a negative
leap-seoond, 23h 59m 58s will be followed one second later by 0h 0m 0s
of the first day of the following month (see Annex III).
2.3 The IERS should decide upon and announce the introduction of a
leap-second, such announcemtn to be made at least eight weeks in advance.
--
James Maynard, K7KK
Salem, Oregon, USA
