2020 is leap year, which means, February gets an extra day, as it does every four years. But what is leap year and why do we have it?

A leap year is a calendar year in which an extra day is added to the Gregorian calendar, which is used by most of the world. Adding an extra day every four years keeps our calendar aligned correctly with the astronomical seasons. Without the extra day, our calendar and seasons would gradually get out of sync. If you happened to be born on leap day, you are a “leapling.”