How did the extra day get added to the year? And why was it added to February? We did a little research to find out the answers to those questions and a few more.  

Let’s Add a Day or More 

In the ancient world, different cultures had their own calendars – some were running on lunar cycle calendars, while others used the sun to dictate their year. There were many experiments to draw the calendar in line with the seasons.    

Imagine you live in ancient Rome. That could be almost anywhere in today’s Europe. Romans were excellent problem solvers. Think about their road systems, the aqueducts, their ability to muster thousands of people behind a common cause. Even with all that, it took the Egyptians to help them with their calendar.  

The first Roman king, Romulus, declared that the year started in March (called Martius) and was only 10 months long. Winter didn’t even matter because people weren’t working during those days. In frustration with the wishy-washiness of arbitrary time, the second Roman king, Numa Pompilius decided it was time to start counting winter, so two more months were added to the calendar. Even that was not enough to keep the seasons in line with the calendar, so Roman consuls would add a thirteenth month to the calendar every two years or so.  

Then came Julius Caesar, who with the help of an advisor to Egypt’s Cleopatra, established the Julian calendar in 45 B.C.E. The calendar was based on a calculation of 365 days and six hours for a trip around the sun. Every fourth year, an additional day was added – Caesar made it a “double day” where two days counted as one (February 24 was 48 hours long). Even with adding the extra day every four years, the calendar got out of step with the seasons because of an extra 11 minutes that weren’t accounted for.  

Those 11 minutes added up to a 10-day discrepancy by the 16th century. Pope Gregory XIII introduced a new calendar to account for those small increments in the 1570s. What was the answer to help align the 11 minutes? A leap day would be added every four years except centurials unless they were divisible by 400 – so 1800, 1900, and 2100 would not be leap years, but 1600, 2000, and 2400 would. Can you imagine the mathematical formula used to make this calculation?  

Of course, it took some time for the world to adopt the Gregorian calendar as the international standard. That’s part of what accounts for Old Christmas being celebrated in the Appalachian Mountains on January 6 (the 12-day skip ahead in September 1752 in Britain to bring the calendar up to date was not embraced by all). Even with all of that, there’s still the 11-second difference that will be abandoned by timekeepers altogether in 2035.  

It Happened in a Leap Year 

History records over 100 leap years since the mid-1500s when the calendar was standardized and even more since Leap Year was first established by Julius Caesar. That’s long enough for a few things to happen and for groups of people to develop superstitions around not only the day but the year itself. 

According to Time & Date, the Scots believe it is bad luck to be born on a Leap Day. The Greeks take it a few steps further by believing it is bad luck to be born in a Leap Year.  

Legend tells us that St. Brigid, the patroness saint of Ireland, and St. Patrick came to an agreement to allow women to propose marriage to men one a single day every four years – Leap Day.  It’s believed that this was an effort to balance out the roles of men and women in the same way that Leap Day balances the calendar. 

There are important historical events that happened in Leap Years. The Black Death, which ran rampant through Europe in the Middle Ages, killing between 30 and 50 percent of the European population, reached its peak in 1348. 

The first modern Olympic Games were held in Athens, Greece, in 1896. In 1912, the RMS Titanic sank on its maiden voyage, and the first oral contraceptive pills in the United States were approved by the Food and Drug Administration in 1960. 

What a Leap Day 

Leap Years are eventful, and so are Leap Days. Those who are born on Leap Day are called Leaplings. And speaking of being born on February 29, according to the Guinness Book of World Records, the Keogh family holds the record for most consecutive generations born on Leap Day with three – Peter Anthony (Ireland, born 1940), his son, Peter Eric (UK, born 1964), and his grand-daughter, Bethany Wealth (UK, born 1996).  

That's pretty amazing, but there’s also a family where all the siblings were born on Leap Day. Heidi (1960), Olav (1964), and Leif-Martin (1968), the children of Karin and Henry Henriksen of Norway, all celebrate their birthdays every four years.  

What else happened on Leap Day? In 1936, the Soviet government re-named the First Leningrad Medical Institute The Pavlov Institute. They took this action to recognize Ivan Pavlov’s research into conditioning to behave with a learned reflex. The renaming was just two days after Pavlov’s death and his brain is preserved there. 

In 1940, actress Hattie McDaniel won an Oscar for Best Supporting Actress for her role as Mammy in Gone with the Wind. She was the first African American to win an Academy Award. Henry Aaron signed a three-year contract with the Atlanta Braves in 1972 for a league record (approx.) $200,000 per year, making him Major League Baseball’s highest-paid player.  

On February 29, 1692, the first warrants for arrest were issued in the Salem Witch Trials. On that day, Salem residents Sarah Good, Sarah Osborne, and Tituba were accused of witchcraft. Good was hanged; Osborne died in prison; and Tituba, who admitted to the accusations, was later released from jail. 

Do You Want to Read More? 

There are some great resources out there to learn more about Leap Day, Leap Years, and the science and history behind them. Here are some suggestions: 

The Old Farmer’s Almanac - 2024 Is a Leap Year! When Are Leap Years and Why Do We Have Them? 

Slate - The Math Behind Leap Years 

The Smithsonian - The Science of Leap Year 

Time – Who Decided February 29 is Leap Day 

Happy Leap Day!  

 

Images

Caesar - Image by Efry E from Pixabay 

(1910) A Physician Wearing a Seventeenth Century Plague Preventive Costume. , 1910. [Place of Publication Not Identified: Publisher Not Identified] [Photograph] Retrieved from the Library of Congress, https://www.loc.gov/item/2021669921/

Matteson, T. H. Trial of George Jacobs of Salem for witchcraft, Essex Institute, Salem, Mass. Salem Massachusetts, None. [Between 1900 and 1920] [Photograph] Retrieved from the Library of Congress, https://www.loc.gov/item/92515055