Computer bugs in the year 2000

[Dave Martindale]

In article <974 at utastro.UUCP> nather at utastro.UUCP (Ed Nather) writes:
>The year 2000 *is* a leap year, despite what many algorithms tell you.
>The year 2400 is *not* a leap year.
>
>With minimal effort, you can make things work until 2399.  You may be
>subject to complaints after that.

Are you absolutely sure of this?  (your trailer DOES say you work come
from an astronomy department....)

My understanding was that years divisible by 4 were leap years, except
 that years divisible by 100 were not, except that years divisible by
 400 were - giving 97 leap days every 400 years.

According to that pattern, 2000 IS a leap year, and the naive year-mod-4
algorithms will work properly until 2099, not 2399.