Testing For Leap Year

Oct 18, 2009
Not quite. That's what Y2k was about. Centuries are only leap years if they are evenly divisible by 400, i.e., 1700, 1800 and 1900 were not leap years but 2000 was, but 2100 won't be.

Doesn't seem like a big deal but the Y2k problem was originally noticed in 1970 when calculations on 30-year mortgages were being done.

(Mortgages almost never are more than 30 years because beyond that the monthly payment is almost the same regardless of length, i.e. the difference between a 30 year vs. 40 year mortgage at the same interest rate might be $50 a month.)