Quick quiz: how many days are there in February this year? Getting to the correct answer may seem easy, but it involves making a few detours to check out distant stars, the Earth's spin, and even a few groundhogs. Counting the days in February 2000 should mean including a leap day because any year divisible by four has an extra day.
On the other hand, century years-those ending in double zeros-ordinarily do not have a February 29; 1700, 1800, and 1900 didn't have this additional day. But once every four centuries, the double-oh year is a leap year, and 2000 is one of them. So there will be a February 29 this year.
How did this get so complicated? Basically, people like nice whole numbers, but nature does not oblige. Measured against the stars, an Earth year lasts 365.2422 days-365 days, 5 hours, 48 minutes, and 46 seconds. If the ...
