Originally posted by XanthosNZWhy does that rule exist (re: years ending in 00)?
Taking the date of the Union Jack adoption to be 1801 (An earlier version was used to represent England + Scotland from 1606 but that isn't all of GB) we find that we have leap years from 1804 to 2004. So that would be 51 leap years. EXCEPT that 1900 was not a leap year as years divisible by 100 are not leap years unless they are divisible by 400 (1900 was not, 2100 will not, 2000 was).
Originally posted by ThudanBlunderAlready we know about leap seconds, because the earth does not rotate at a totally steady rate, some years it slows down a bit and other years it speeds up so that will throw everything off in due time.
And there are three rules, not two. In the future they might have to invent a fourth.
Originally posted by Fat LadySomehow I don't think we will be worrying about that in 8000 years!
The three rules the Gregorian Calendar uses to define leap years approximate the number of days in a years as:
365 + 1/4 - 1/100 + 1/400
which is equal to 365.2425
Currently there are approximately 365.242375 days in a year, which suggests that we will be 1 day out in 8000 years time. However the number of days in a year is changing and is not predictable, so other fudge factors may be needed before then.