## What is leap year?

Leap year is a year which occurs once every four years, such years has 366 days includes February 29 as an extra day. Except for century years whose number is not divisible by 400.
## How to calculate leap year?

In Gregorian calendar any year should satisfy the below three main criteria:

- A year should be evenly divided by 4;
- If a year is divisible by 100 then its not a leap year, unless;
- A year is also evenly divided by 400. Then it is a leap year.

For example, year 2000 and 2400 are leap years even though they are divisible by 100 they are also divisible by 400.

But 1800, 1900, 2100, 2200, 2300 and 2500 are **not** leap years because they are not divisible by 400.

## Leap Year 2000

The year 2000 is the very first year where the third criteria was used in Gregorian Calendar.

## Who Invented Leap Years?

Julius Caesar replaced moon calendar with the Egyptian calendar, which was regulated by the sun. He set the length of the year to 365.25 days by adding an intercalary/leap day at the end of February every fourth year.

### Upcoming Leap Years

2020, 2024, 2028, 2032, 2036, 2040,

### Past Leap Years

2016, 2012, 2008, 2004, 2000, 1996,

### Leap Days

Year | Day of week - February 29 |

2000 | Tuesday |

2004 | Sunday |

2008 | Friday |

2012 | Wednesday |

2016 | Monday |

2020 | Saturday |

2024 | Thursday |

2028 | Tuesday |

2032 | Sunday |