Re: YEAR 2000 Problem with existing Databases

proberts_at_isc901.jsc.nasa.gov (Paul Roberts) wrote:

>BTW, you should know that the year 2000 is NOT a leap year in the
>Gregorian calendar!!! I know that its divisible by four, but there's
>this little exception to that rule that says if its divisible by 400,
>its not really a leap year.

Well, this is simply NOT true. The correct rules are:

1. year MOD 4 = 0 --> is leap year
2. year MOD 100 = 0 --> is no leap year
3. year MOD 400 = 0 --> is leap year

 (where year is 4-digit of course!)

eg. 1996 is a leap year

    1900 was NO leap year
    2000 will be a leap year

Rule 2) & 3) cause that between 1901 and 2099 every 4th year IS a leap year. So you get correct results when you use just rule 1) here ...

Hope this helps to clear up any possible confusion.

--
Michael Kiesel
mkie_at_izb.de