It’s leap year yet again, but what exactly is all this jumping about?
To get to the start of leap years, you have to go way back to the year 45 B.C. Julius Caesar was on a quest to create a calendar that could be used by everyone that wouldn’t fluctuate with the moon or the sun, known as a solar calendar. The intent is to keep the seasons from moving throughout the year. When building this calendar, he realized that a year wasn’t quite 365 days exactly, but instead 365.2422 days long. To correct this, he added one day to the month of February every four years. But even this wasn’t quite perfect. That extra 0.0022 days means that every 400 years, the calendar will still drift by three days.
The story wouldn’t change again until 1600 years later when the Catholic Church became concerned about the drift — by this point, a full ten days — and began work on the Gregorian Calendar. The main concern was over the drift of the March equinox, which is important in the calculation of Easter Sunday. It had drifted well off its average March 21 date. So, in 1582, the church decided to skip forward from Thursday, October 4, to Friday, October 15, and instate a new rule for leap years going forward.
New rule
The new rule was that every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100, but these centurial years are leap years if they are exactly divisible by 400. For example, the years 1700, 1800, and 1900 are not leap years, but the years 1600 and 2000 are.
This new rule approximates each year to be 365.2425 days long, much closer to the 365.2522 days it actually is. Thus, the calendar drift is reduced to nearly nothing over long periods of time.
The term “leap” year likely refers to the fact that between two regular years in the Gregorian Calendar, any given day will shift by 1. For example, Christmas Day fell on a Sunday in 2022 and Monday in 2023. For 2024 it will “leap” over Tuesday and fall on a Wednesday.
Since the creation of the special day, February 29 has taken on a life of its own outside of scientific necessity. It has become the focal point of many traditions around the world. In Ireland, Britain, Finland, and various other countries, it is tradition that a woman may propose to a man only on Leap Day. In Finland, if the man refuses the proposal, he is required to buy the woman the materials for a skirt. In Greece, marriage during a leap year is considered unlucky, leading many couples to avoid it. In France, a special newspaper called La Bougie du Sapeur is published only on Leap Day.
Here in the US, the town of Anthony, Texas, has declared itself the “leap year capital of the world.” It is the home of an international “leapling” birthday club.
Speaking of birthdays… a special HAPPY BIRTHDAY to anyone who was born on February 29th! It is unknown exactly how many people share a birthday with you, but the estimate lies around only 5,000,000. That’s only 0.06% of the Earth’s 8 billion people. Throughout most of the world, people born on February 29th commonly celebrate their birthday on February 28th in a non-leap year. In many countries, this has been written into law to erase any confusion.
So, on this Leap Day, be sure to do a quick jump on the way to work or school and remember you get one extra day this year, so make it count!
