quote:

Originally posted by architect:

Don't forget that years that end in 00 have their usual leap day dropped to further adjust to the discrepancy between the solar and lunar cycles.

Note also that orbits decay and our current conventions will not be valid for the long term.

You are 75% correct. Century years are leap years only if the year is evenly divisible by 400. 1600 was a leap year, as was 2000. 1700, 1800, and 1900 were not leap years, nor was 2100.

I remember that piece of mostly useless information because around 1970 I was working for Western Union in their message switching computer division. We had some sort of requirement that was date-dependent and I coded a function that would return the difference between two dates, working in Univac 418 assembly language.

quote:

Originally posted by architect:
Don't forget that years that end in 00 have their usual leap day dropped to further adjust to the discrepancy between the solar and lunar cycles.

Note also that orbits decay and our current conventions will not be valid for the long term.

How come the year 2000 had a leap day? (According to the calendar)

^^^ read the one above yours

Happy 229 Day

quote:

Originally posted by architect:
Don't forget that years that end in 00 have their usual leap day dropped to further adjust to the discrepancy between the solar and lunar cycles.
<snip>

The lunar cycle has nothing to do with leap year intervals. Leap year rules adjust our calendar to make it make it more closely conform to the true earth year (currently ~365.2422 days).

quote:

Originally posted by architect:
Note also that orbits decay and our current conventions will not be valid for the long term.

Hence leap seconds, no?