Why is a Leap Year Necessary?
Leap years are added to the calendar to keep it working properly. The 365 days of the annual calendar are meant to match up with the solar year. A solar year is the time it takes the Earth to complete its orbit around the Sun — about one year. But the actual time it takes for the Earth to travel around the Sun is in fact a little longer than that—about 365 ¼ days (365 days, 5 hours, 48 minutes, and 46 seconds, to be precise). So the calendar and the solar year don’t completely match—the calendar year is a touch shorter than the solar year. It may not seem like much of a difference, but after a few years those extra quarter days in the solar year begin to add up. After four years, for example, the four extra quarter days would make the calendar fall behind the solar year by about a day. Over the course of a century, the difference between the solar year and the calendar year would become 25 days! Instead of summer beginning in June, for example, it wouldn’t start until nearly a month la
