Leap year adds extra day to February 2016


The last time we had an opportunity to publish this paper on Feb. 29 was in 1996. For that, we have Julius Caesar to thank.

Leap days, that extra day tagged on to the end of February every four years, correct a slight inaccuracy in the Gregorian 365-day calendar. Earth’s orbit around the sun is actually about 365.24219 days, meaning that with every passing year, the calendar is thrown off by almost a quarter of a day. This means that every 100 years, our calendar would be ahead of the corresponding positions in the orbit by a whole month. After 700 years, Christmas would be celebrated in the Northern Hemisphere during the height of summer.

So to prevent the calendar year from slowly slipping out of sync with our calendar months and seasons, leap days are added every four years to realign the calendar year to the orbit. The ancient Egyptians initially realized this discrepancy and Caesar officially instated leap days in 46 B.C. to the Julian calendar. They have since been adapted by the Catholic Church’s Gregorian calendar, the most widely used calendar today.

Even then, it’s not so cut-and-dried. Leap days overcorrect for that .24219 remainder of a day just a little bit, so every 100 years, we skip a leap day. But then that over-corrects the other way, so every 400 years, we skip a skip.

Whether people are aware of the purpose of leap years or not, Feb. 29 has become an interesting cultural fixation across different societies worldwide. Are our leapling friends, those born on a leap day, actually considered 24, or are they technically six?

Previously, Feb. 29 birthdays did not show up on Facebook at all during common years. Now, leapling birthdays automatically show as either Feb. 28 or Feb. 29. Legally, many countries will only recognize a Feb. 29 birthday as March 1 in common years. England, Wales and Hong Kong recognize leaplings as turning 18 only on March 1, the start of their next year. In New Zealand and Taiwan, on the other hand, their legal birthday would be considered Feb. 28.

In the United States, there are no general statutes regarding leap-year birthdays, according to John Reitz, a law professor at the University of Iowa. However, Reitz suggests that for most cases, March 1 would be considered the legal birthday in common years.

Dana Warshauer (A.B., ‘10), director of Parent Relations and a leap-day baby, consistently celebrates her birthday the day after Feb. 28, whether it’s called Feb. 29 or March 1.

“Sometimes I find people feel bad [because]I don’t have a birthday every year, which isn’t really the case, so I’ve never really understood their concern,” said Warshauer, who was born in 1988. “It’s a great topic of conversation and it’s my go-to when I need to share a fun fact. More importantly, I share a birthday with Ja Rule and with Superman, so I’ll take it.”

Featured image courtesy Pixabay user Unsplash


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