Why do we get a bonus day tomorrow but won’t get it again until February 2024?
Thanks to our ‘messy’ solar system, a kink in the Earth’s orbit, a Roman emperor and a 16th-century pope, every four years, February is super-sized with an extra day. So, why does this happen?
Leap years were created because of the time it takes our planet to make a complete orbit around the Sun. According to our calendar, it takes 365 days for the Earth to revolve around our nearest star. Well, this isn’t quite correct. It takes about 365 days and six hours. Therefore, every four years, we’re one day behind where we should be to reflect the Earth’s position around the Sun. To keep us synchronised an extra day is inserted into February every four years.
However, this isn’t the end of the story, because it takes slightly less than 365 days and six hours for our home to make a complete orbit of the Sun. So when Pope Gregory XIII introduced the Gregorian calendar in 1582 (the calendar still used in most of the world), he decided to lose three leap days every 400 years. This is why some years there aren’t leap years even though you might expect them to be.
Leap years were invented by Julius Caesar and his astronomers when they noted that the 355-day Roman calendar was out of sync with the seasons. The new Julian calendar worked well for hundreds of years, but by the time we get to the 16th century, the calendar and the seasons were off by 11 days. Pope Gregory corrected this.
In some languages such as French, Italian and Spanish, a leap year is referred to as a bissextile year. This is the technical name, and it comes from a Latin phrase the Romans used for their leap year, which was the sixth day before the Kalends (first day) of March: ante Diem bis VI Kal. “Bis” means “twice,” hence the word bissextile.
Traditions and Customs
Although the concept exists for purely astronomical reasons, many parts of the globe have leap year traditions and customs.
• In several countries, women traditionally propose to their partners on the 29th of February. Although no one is sure where this originates from, there are several candidates. One popular legend has it that in the fifth century St. Bridget complained to St. Patrick that women have to wait a long time for their boyfriends to propose. So, St. Patrick gave women a single day in a leap year for them to propose.
• In some European countries, if a man turns down a woman’s leap year proposal of marriage, he has to buy her 12 gloves. This isn’t so that she can stay warm; it’s to hide her embarrassment at not having an engagement ring.
• La Bougie du Sapeur is a humorous French newspaper that is published once every four years, on leap day. The first edition was launched on the 29th of February, 1980, and it has appeared every leap day since.
• People who are born on the 29th of February are invited to join the Honour Society of Leap Year Day Babies, a free-membership birthday club.
• In Greece, leap years can bring bad luck. It is said that marriages that take place in a leap year will end in divorce.
• In Taiwan, married daughters who follow the leap year tradition bring their parents’ pig trotter noodles during February. The food offering is to wish them good health and fortune.
What are you going to do with your extra day this year? If you’re a woman hoping to pop the question – good luck!