A leap year consists of 366 days. During Leap Year, we add a leap day, an extra day on February 29. Leap years are important because we need to keep our calendar in alignment with the Earth's revolutions around the sun. It takes the earth approximately 365.242199 days or 365 days, 5 hours, 48 minutes and 46 seconds to circle once around the sun. However the Gregorian calendar has only 365 days in a year, so if we didn't add a day on February 29 nearly every 4 years, we would lose almost six hours off our calendar every year. After 100 years, our calendar would be off by approximately 24 days!
How to find out that the given year is a leap year?
Any given year is a leap year if it is divisible by 4 but not by 100. If a year is divisible by 4 and by 100, it is not a leap year unless it is also divisible by 400.
For example, years such as 1992, 1996, 1988 and so on are leap years. They are divisible by 4 but not by 100. In case of century years, the 400 rule applies. Thus the century year 1900, though divisible by 4 is not a leap year. It is divisible by 100 but not divisible by 400. The century year 2000 is divisible by 4, is divisible by 100 but also divisible by 400. Thus it is a leap year.
