A Leap Year comes around every four years unless... of course, it couldn’t be that simple! The present calendar, which came after the old Julian calendar, was revised under Pope Gregory XIII in 1582. The Gregorian calendar kept the extra day every four years, except in years that ended in 00 — unless those years were divisible by the number 400. For example, the year 1900 would not have an extra day, but the year 2000 would have (because 2000 is divisible by 400). It sounds complicated, but the Gregorian calendar was a simple improvement over the Julian, and most of the world adopted it. Here are some fun facts about the Leap Year that’s really worth to know: 1. What is a Leap Year, and why do we have it? A leap year is a year containing one additional day (February 29) added to keep the Gregorian calendar (365 days) synchronized with the orbit of the earth around the sun, which is about 365.2422 days. 2. Why February? During the reign of the Roman Emperor Julius Caesar...