Computer bugs in the year 2000

[Gary Marc Levin]

>       I have a friend that raised an interesting question that I immediately
> tried to prove wrong.  He is a programmer and has this notion that when we
> reach the year 2000, computers will not accept the new date.  Will the
> computers assume that it is 1900, or will it even cause a problem?
>  ...
> Spencer L. Bolles

The problem won't be the computers, but the software.  Some software is
bound to be wrong, only considering the last two digits of the year.

Actually, the year 2000 will probably make some faulty software work
correctly for 100 years longer than they should.  2000 is the second
level exception to the leap year rule.

    Leap years are those years divisible by 4,
    EXCEPT those divisible by 100,
    EXCEPT those divisible by 400.

Programs that assume that all multiples of 4 are leap years are wrong,
but the problem won't come up until 2100.
-- 
Gary Levin / Dept of CS / U of AZ / Tucson, AZ 85721 / (602) 621-4231