Today is Leap Day and 2016 is a Leap Year, but do you know why?
Would you believe that it all started with the ancient Sumerians that lived around 3,000 BC? They created a simple calendar that was evenly divided in 12 months, each having 30 days. This gave them a 360-day week which was fine at first, but in time the 5-day discrepancy added up and threw the seasons way out of whack when compared to their calendar so they would randomly add days to their calendars.
Many other cultures used lunar calendars to track time, but they also have a problem since a lunar month is only 29.5 days resulting in a 354-day year. This led to even more problems with keeping up with the seasons and the yearly orbit around the sun. Some cultures, like the Romans, would sporadically add weeks and even months to the calendars to make up the difference.
For centuries, astronomers said that it took 365.25 days for the earth to rotate around the Sun. In an effort to come up with a more accurate calendar, Julius Caesar developed what is known as the Julian calendar of 365 days with a leap day added every four years on February 29. However, before he instituted his new calendar, he had to make a huge correction to the current timing, so in 45 BC, he declared a Year of Confusion which consisted of 445 days. At the end of the Year of Confusion, the Julian calendar could be started.
The Julian calendar was used for over 1,000 years, but it also had its problems. The actual time it takes the earth to orbit the Sun is 365.2421 days, not 365.25 days. Over the course of 128 years, the Julian calendar was a day ahead of the annual solar orbit. Over a number of centuries, that extra day added up and created problems holidays and other special dates.
In the 1580s, Pope Gregory XIII decided to make some adjustments to the Julian calendar. In 1582, he ordered 10 days in October to be removed that year only in order to bring the calendar in alignment with the true solar year. Then he devised a formula to avoid that addition of the extra days. Every four years would be a leap year with a February 29 leap day, except for years that were evenly divisible by 100 but not evenly divisible by 400. For example, the 1900 is evenly divisible by 100 but not by 400 so it was not a leap year. The year 2000 is evenly divisible by both so it was a leap year. 2016 is not evenly divisible by 400, so it is a leap year and today is leap day.
The Gregorian calendar, initiated in 1582 is the calendar we still use today. However, it also has a problem. It’s the closet to a true solar year, but still has a slight discrepancy. Most experts believe the discrepancy will add up to the point that it will need to be addressed in about 10,000 years.
In many cultures, leap year and leap day are superstitiously treated something like a Friday 13th. Some cultures refrained from planting crops in leap years because they believed they would not produce well. Others would not allow legal agreements or documents to be made or signed in leap years fearing they would end badly.
Did you know that on leap day, February 29, 1692, Sarah Goode and Tituba were accused of witchcraft? They happened to live in Salem, Massachusetts and it was this leap day event that set off the hysteria that plagued the town, leading to the infamous Salem Witch Trials.
Legend has it that in the 5th century, the Irish started a tradition of allowing women to propose to men on February 29. In 1288, the Scottish parliament passed the Leap Year Act which made it legal for women to propose to men on February 29, every four years.
In 1504, Christopher Columbus used his knowledge of the calendar and astronomy to secure food for his men. He was in Jamaica and the local Indians decided to stop providing the explorers with food. Columbus knew that there would be a lunar eclipse that year, on February 29, so he told the Indians if they refused to help him that God was displeased with them and would give them a sign in the sky to show His anger and that would be followed by famine and pestilence. When eclipse happened, the moon turned dark and reddish, the Indians were greatly frightened and once again began providing food for Columbus and his men.
People born on February 29 are known as ‘leapers’ or ‘leaplings.’ Technically, they only have a birthday once every four years and if there is a year with no leap day, it may be eight years between birthdays. They sometimes run into problems with computer systems that don’t recognize February 29, making it hard for them to obtain driver’s licenses, loans and handling other legal issues. Facebook eventually realized that they needed to make changes to their profiles so that leapers could record their birthdays.
There are a number of celebrities, athletes and notable others that were born on February 29 and can be found listed in some of the sources below. Perhaps the most famous leaper is the fictional character Superman.
If you’re a leaper, enjoy your special day.
Sources for the above include: A brief history of Leap Year; Why do we have leap year?; The Surprising History Behind Leap Year; Today in History – February 29; All About Leap Day; February 29 Birthdays