February 14, 2020

Julius Caesar, leader of the Roman Empire, was the first person who confronted this problem and sought to create a standardized calendar that reflected the seasons. “After working with astronomers, Julius Caesar discovered a solution he believed would fix the inconsistency in the calendar system,” Krisciunas said.

In 46 B.C., Caesar introduced the Julian Calendar. This new calendar was constructed around months of the year to create the 365-day calendar year. On the advice of an astronomer named Sosigenes, Caesar also added that every four years, an extra day would be added to Februarius (February) to account for the slightly longer length of the solar year.

Although Julius Caesar was the one who introduced the idea, it was later discovered that his math wasn’t exactly right. “By the late 1500s, the Julian Calendar had contributed to a 10-day difference in the calendar,” Krisciunas said. “Caesar had the right idea, but his calendar continued to move noticeably out of sync, prompting a second calendar reform in 1582 from Pope Gregory XIII.”

Taking the new calculations into account, Pope Gregory established a new calendar that included the “century rule.” The century rule stated that instead of consistently happening every four years, leap days would not be added in years ending in “00” unless the year was also divisible by four. (So, while the year 2000 was a leap year, the years 1700, 1800 and 1900 were not.) This rule and other additional corrections created the calendar system we currently use today: the Gregorian Calendar.

“The Gregorian Calendar’s original goal was to restore many days of religious significance back to their original date, including returning the vernal equinox to March 21,” Krisciunas concluded. “Because of this, some countries rejected the new system due to its ties to the pope. It wasn’t until the mid-1700s when almost all countries officially adopted the Gregorian Calendar.”

Leap Year Traditions, Celebrations and Superstitions

  • One of the most widely practiced leap day traditions can be traced to 5th-century Ireland. At the time, it was common practice that proposals were solely a gentleman’s privilege. However, during leap day, the roles were reversed and matrimony-minded women were presented the chance to propose to their man instead. In Scotland, the tradition is still taken very seriously, requiring men who refuse a proposal to pay a fine. In the United States, this tradition inspired an American adaptation known as Sadie Hawkins dances, in which girls ask boys to be their dates.
  • Known as the leap year capitol of the world, Anthony, Texas, boasts a huge four-day festival celebrating leap day in style. People travel from all over to take part in parades, hot air balloon rides and birthday dinners celebrating leap day babies.
  • Many cultures believe being born either on leap day or during a leap year is bad luck. In Scotland, it’s thought that people born on Leap Day are doomed to have bad luck forever. Likewise, in Russia, Taiwan and Italy, leap day is not met with happiness. The Italians have a saying, “anno bisesto, anno funesto,” which translates to “leap year, gloomy year.”
  • Those whose birthdays fall on Feb. 29 are known as “leapers” or “leaplings.” They usually celebrate their birthday on Feb. 28 or March 1 depending on their state of residence. The odds of being born on Leap Day are 1 in 1,461, although if you’re lucky enough to beat those odds, you gain exclusive membership to the Honour Society of Leap Year Day Babies. Once every four years, people born on Feb. 29 can celebrate on their actual birthday.

Dr. Krisciunas joined the Texas A&M Department of Physics and Astronomy faculty in 2006 as a member of the George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy. The physics department has greatly benefited from philanthropic contributions made by the late Cynthia and George P. Mitchell ’40 and their associated family foundation. The Mitchells’ total commitments to Texas A&M exceed $95 million, including more than $88 million that helped build two new physics buildings and establish a world-class astronomy program.