What is a leap year and why do we sometimes have it? A leap year is a special year which the Gregorian calendar uses to correct the skewing that would otherwise happen without adding an extra day to a year every four years. In the Gregorian calendar, the most commonly used calendar in the world, the year is actually a little more than 365 days. To be precise, a year is actually 365.24 days. So what do we do with that extra 1/4 day? We add it up every four years to make a full day which we then add to February.
We do this because the calendar is designed to be in sync with seasons. If this extra quarter day was left to its own devices, it would slowly and inexorably skew our calendar so that eventually winter would be in June. Nobody wants that, so this is why we do it.
The next leap year is 2008. If you are not sure of when the leap years will be, remember this simple rule: Every year that is exactly divisible by 4 will be a leap year. So hold on to your hats! Leap year is coming up!