What is a leap year? A leap year is a year in which one extra day has been inserted, or intercalated, at the end of February. A leap year consists of 366 days, whereas other years, called common years, have 365 days.
Which years are leap years?
In the Gregorian calendar, the calendar used by most modern countries, the following three criteria determine which years will be leap years:
- Every year that is divisible by four is a leap year;
- of those years, if it can be divided by 100, it is NOT a leap year, unless
- the year is divisible by 400. Then it is a leap year.