For a day that happens only every four years, and in rare cases separated by eight years, Feb. 29 has a lot going on — everything from science to superstition.
Earth’s yearlong revolution around the sun isn’t tidy: It takes 365.24219 days to complete the circle, leaving us with some spare change that adds up to an extra day almost every four years. Because Earth’s annual revolution is a little short of a quarter of a day, there are rare occasions when there is no leap year.
Years that are divisible by 100 but not by four aren’t leap years. The turn of the 21st century — 2000 — was a leap year, but the years 1700, 1800 and 1900 weren’t, and there won’t be one in 2100.
Leap year’s origins go back to ancient astronomy. The Egyptians created a 365-day solar calendar but realized it wasn’t accurate and also maintained a lunar calendar to compensate for the extra time.
In 46 B.C., during Roman emperor Julius Caesar’s reign, an extra day — Feb. 29 — was added to the calendar every four years. Sixteenth-century astronomers refined the calendar to account for the 365.24-day year in the Gregorian calendar still used today.
People born on a leap year — also known as leaplings or leapers — sometimes have a tough time of it. Most of their lives, they have to celebrate their birthday on another day — usually Feb. 28 or March 1, and sometimes both.
Famous leaplings include 16th-century Pope Paul III, composer Gioachino Rossini, bandleader Jimmy Dorsey, singer Dinah Shore, actors Ken Foree and Dennis Farina, hockey player Cam Ward and rapper/actor Ja Rule. A fictional celebrity — Superman — was born Feb. 29, according to references in the comic books.
Feb. 29 is most famously associated with a tradition in which women were allowed to propose marriage on that rare date. The custom is thought to have originated in Ireland, where legend has it that St. Bridget petitioned St. Patrick for a day when women could pop the question.
Babies born Feb. 29 were considered unlucky and not just because they were cheated out of three-quarters of their birthdays. They were thought to be hard to raise and prone to illnesses. The Greeks thought that getting married or starting any kind of contractual relationship in a leap year was a bad idea.
The 1940 Academy Awards were handed out on Feb. 29. It was a milestone Oscar year: Hattie McDaniel became the first African-American to win for her work as supporting actress in Gone With the Wind.