Nearly every four years, we add an extra day to the calendar – February 29th – to make sure that the Gregorian calendar stays in sync with the Earth’s movement around the sun. This holiday, rooted in scientific discovery, has historically been home to curious superstitions and new, exciting celebrations. 

The existence of leap years derives from the amount of time it takes for the Earth to complete one orbit around the sun. Though most years are 365 days long, a single orbit actually takes around 365.24190 days. Though these extra five hours and 48 minutes may seem trivial, without leap years, our seasons would begin to shift, and summer would start in December!

Though these exact numbers were only recently discovered with modern technology, the existence of leap years (or months) has been documented in ancient societies as well. Ancient Hebrew, Chinese, and Buddhist calendars, all of which operated on lunar movements, periodically added extra months, known as intercalary months, to keep them on track. This type of calendar was introduced to the Roman Empire by Julius Caesar after his time in Egypt, where they added an extra day to the second month of the year, and thus, Leap Day was born. 

Because of its long history across the world, Leap Day has also been home to various superstitions and celebrations. In fifth-century Ireland, St. Patrick designated the day as the one day where women would be allowed to propose to men, coining the term Bachelor’s Day. This tradition was shared across the British Isles, and though it does not hold the same significance as it once did, it is still practiced today. Conversely, in Greek tradition, it is considered bad luck to marry on Leap Day, and modern statistics show that this superstition remains in Greek society. More recently, the holiday has become a large celebration for those born on Leap Day, with the Worldwide Leap Year Festival in Anthony, Texas. 

We hope you enjoy the extra day this year. Happy Leap Year!

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