Catholic Origins of Leap Year

2020 is a leap year, and leap day is this Saturday, February 29th. Why do we have leap years? Scientifically speaking, the earth takes 365.2422 days to complete one revolution around the sun. That means each 365-day year ends a quarter day's worth short of the complete orbit, and that's why we add one day every four years to make up for it. But the leap year has Catholic roots, too; the calendar was altered in 1582 by Pope Gregory XIII to bring the celebration of Easter to the time of year it was celebrated when it was introduced by the early church. But, there were some challenges in the years that followed as nations used different calendars and systems to track the earth's revolutions. Read more about this complicated calendar history in this article from Crux.