- Every four years an additional day is added to the end of February known as "Leap Day."
- Though February 29 occurs infrequently, leap days have seen their share of famous events, births, and deaths.
- Leap days have existed since the time of Julius Caesar. Here are some memorable events that have happened on February 29 over the centuries.
- Visit Business Insider's homepage for more stories.
While a typical year is typically composed of 365 days, every four years the calendar adds one extra day to the end of February to catch up with the solar cycle.
That extra day, February 29, is known as "Leap Day."
Though it's the rarest day on the calendar, a number of significant events have occurred on Leap Day since since its inception in 45 B.C.
Here are the most important historical events February 29 has brought us: