Happy leap year! Feb. 29, 2024, is leap day and marks an ongoing, longstanding correction to the calendar we use.
In most years, our calendar contains 365 days. But Earth actually takes 365.2422 days (let’s call it 365¼ days) to orbit the Sun. As you might imagine, if we let these quarter days add up, we’d quickly be celebrating the 4th of July in America when it’s snowing.
So, we add a full day every four years … almost. A year that’s 365¼ days long actually is 11 minutes longer than Earth’s actual orbit. That means we need additional corrections from time to time. Years divisible by 4 are leap years, except for centurial years that cannot be divided evenly by 400.
By the way, the first one added to the month of February occurred in the year 8 A.D. The most recent leap year (before this one) was in ...
