Forget Y2K, It's Leap Year

Just as it appears the world's computers have smitten the Y2K bug, officials say there could be another date problem on February 29th.

That's because of a little-known calendar rule that determines whether a year is a leap year or not.

Normally, leap years are every four years except for years ending in double-zero.

Many computers may assume that's the case this year -- and incorrectly skip February 29th.

But if a year is evenly divisible by 400, another rule comes into effect that again makes it a leap year.

It's an exception to an exception that only comes into play every 400 years.