On 2012-04-12 19:33, Steve Allen asked:
A well circulated piece of trivia is that 1972 was the longest year in recorded history because civil time contained two leap seconds. I offer this challenge: What was the second longest year in recorded history, and how many leap seconds did it have?
After 1972, UTC was never delayed against TAI by more than 1 s per year. And before 1972 (and after 1960 when UTC was started), this happened only once, in 1971, when UTC was delayed against TAI by 1.053 838 s (the rate d(TAI)/d(UTC) was 1 + 2.592 ms/d at that time). But of course, this does not answer your question because during "the year" 1971 (the time when UTC indicated 1971, plus the time span of about 107.757 997 ms in UTC when UTC was >= 1972 but before TAI reached 1972 + 10 s), TAI only gained about 365 d + 1.05 s which is nearly a day less than what TAI gains in any leap year of UTC. So the expected answer probably is any leap year > 1972 with a positive leap second (1976, 1992, 2008, 2012), where one may even remark that, in terms of the TT time scale, 2008 and 2012 are slightly longer than 1976 and 1992, and that 2012 may not belong to recorded history yet. Or you mean a year before 1960 but then it is not clear to me which time scale you use for determining the years (instead of UTC) and which to measure their lengths (instead of TAI). Michael Deckers. _______________________________________________ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
