Why couldn't it have been a whole number?

Today is leap year day. Here's a simplified explanation of why and when we have it.

• The Earth orbits the sun every 365.2425 days.

• To make up for that .2425 day, one day is added to our calendar every 4 years.

• But one-fourth of a day does not equal .2425.

• Therefore, years which are divisible by 100 are not leap years, unless they are also divisible by 400, in which case they are leap years.

• 1600 and 2000 were leap years, but 1700, 1800 and 1900 were not.

• 2100, 2200, 2300, 2500, 2600, 2700, 2900, and 3000 will not be leap years, but 2400 and 2800 will be.

Image from the Creation Museum