We’ve all been there – last year’s birthday was on a Saturday and you’re looking forward to another weekend birthday celebration, only to be bamboozled by Leap Year. It’s been throwing your holiday, birthday and anniversary celebrations off track since birth. So why do we even have leap day in the first place?
The reason is that for the Earth to orbit the sun, it actually takes around 365 days and six hours or 365.2421 days to be precise. This may not seem that important — after all most of us can easily waste away ¼ of a day on a Netflix binge. But over time, this missing quarter of a day adds up, so an extra day is added on every four years to compensate.
Leap days were first introduced by the Romans in the year 46 BC with the adoption of the Julian Calendar. But it was actually the ancient Egyptians who originally calculated the need for leap days and years. The Romans added an extra day every four years after February 24, the sixth day before the calends or first day of March. Calends or calendae in Latin mean the first days of a month and the English word calendar derives from this term.
There was a slight problem with the Roman system, however. As the solar year is only 0.242 days longer than the regular calendar year, adding a leap year every four years leaves us with a surplus of about 11 minutes. This meant the Roman’s Julian Calendar was off by one day every 128 years. By the time they reached the 14th Century AD, the calendar had strayed ten days from the solar year. To fix this, in 1582 Pope Gregory XIII introduced a new calendar named after himself, the Gregorian Calendar. These extra days occur in each year which is an integer multiple of four, except for years evenly divisible by 100, which are not leap years unless evenly divisible by 400. For example, 1900 was not a leap year because it was divisible by 100 but not 400. This calendar is still used in most countries today, but it is not flawless. The time discrepancy will need to be addressed again in about 10,000 years from now!
The reason we use the word leap to refer to this phenomenon is because dates literally leap or jump in these years. For example, if January 1 is a Tuesday one year then it will always be on a Wednesday the next year when a 365-day cycle is observed. In a leap year, the day of the week moves or leaps forward by two days instead of one. Another more formal term for leap year is bissextile, which derives from the Latin bissextus for the sixth day before March 1.
It’s interesting to note that the regular term used for leap year in Romance languages derives directly from Latin, for example année bissextile in French, año bisiesto in Spanish and anno bisestile in Italian.
A person born on February 29 is called a leap year baby or leapling. Some leaplings observe their birthdays on February 28 or March 1, while others only celebrate every four years.
There is even a special society for people born in a leap year: The Honor Society of Leap Year Day Babies. As if celebrating your actual birthday once every four years wasn’t tough enough, leaplings may also be subject to certain legal implications in some countries. For example, in the UK a leap year baby legally turns 18 on March 1 rather than February 29. They can vote in general or local elections for the first time two days after their actual birthday.
While most of us don’t pay much attention to leap day, there are some interesting customs linked to leap days and years around the world.
Leap Day Customs Around the World
In Ireland this day is known as Bachelor’s Day. Traditionally Irish men propose to women and ask them to dance, but on Bachelor’s Day, the roles are reversed. If the proposal is refused the man is expected to buy the lady in question an expensive dress or coat! There are similar traditions in other European countries. In Denmark if the man refuses a proposal, he is supposed to buy the lady twelve pairs of gloves and in Finland fabric for a skirt.
In Greece it is actually considered bad luck to marry on a leap day. One in five engaged couples in Greece will plan to avoid getting married in a leap year. Russians have an even darker view of these days — they are often associated with freak weather and a higher risk of death.
The Taiwanese also associate these days with bad luck, especially for parents. There is an old country tradition there that married daughters should serve pigs trotters noodle soup to their parents on this day to bring good luck.
Finally, in the Emilia-Romagna Region of Northern Italy people even have a special name for the leap year, l’ann d’la baleina, which translates to whale’s year in English. Italians in this region believe that whales only give birth during leap years.