Feb 29 is Leap Day, but why do we have Leap Year anyway?

Welcome to February, my Limers and Limettes, the mini-month at 28 days… usually. Every four years, though, February gets a one day bonus for that most mysterious of calendar corrections, Leap Year. Coinciding with the Summer Olympics and the US Presidential Election (except in 1900), this quadrennial occasion carries with it a few unique traditions and even some superstition. But aside from women being able to propose to men and making fun of our Leap Year Baby friends for only being a quarter of their actual age, most of us have no idea why February 29th exists at all. So let’s get to it- why do we have Leap Year?

Leap Year frog - Why do we have Leap Year?So Just Why Do We Have Leap Year?

To start, it’s important to know that a calendar year measures (approximately) the time it takes for our big, beautiful Earth to orbit around the Sun. Since we are not the center of the Universe and celestial bodies do not move in time to our systems or position, the time of our orbit is not exactly 365 of our Earth days. It’s actually closer to 365 ¼ and this was first noted in 238 BC as part of the Decree of Canopus, a gathering of Egyptian priests and scientists during the rule of Ptolemy III. To account for this 1/4 day, the Decree proposed amending the existing Egyptian calendar, made up of 12 even 30-day months with a 5-day beginning of year celebration period, to include an extra day on the epagomenal week every fourth year. Unfortunately for Ptolemy III this calendar change didn’t gain popularity and it wasn’t until the Roman Julian calendar was introduced by Caesar in 45 B.C. that the four-year plan of adding an extra day caught on, borrowed from the Egyptians by Caesar’s Alexandrian astronomer, Sosigenes. This went on for about the next 1600 years.

The problem is the Earth’s orbit isn’t 365 and an exact ¼ either, it’s actually 365.2425 (and even this isn’t exactly right either), amounting to a difference of about 11 minutes, 14 seconds. Over the course of 1600 years this moved the Vernal Equinox (and all the other equinoxes as well, for that matter) by about 10 full days. To fix for this slide, in 1582 Pope Gregory XIII introduced the Gregorian calendar, which moved the current date ahead by 11 days and added a process to account for the eleven minutes. To keep us all in line through the centuries, Leap Year is skipped 3 times every 400 years. Put more simply, a century year is not a Leap Year unless it is divisible by 400, giving the years 1600, 2000, and 2400 an extra day but not 1700, 1800, or 1900. Is that really putting it more simply? Probably not, but let’s move on. Now as I’ve noted before, I get emails all the time from our loyal readers asking what the difference is between the Julian calendar and the Gregorian calendar. This is it right here, my friends, the adjustment to have us skip Leap Year every few hundred years. Now I know what you’re saying, surely there must be more to it than that. But I take historical calendar amendments very seriously and would never lead you astray on the matter.

When do Leap Year Babies celebrate?

Ja Rule knows, but do you? Why do we have Leap Year?

There are currently about 4 million folks in the world whose birthday falls on the elusive February 29th, also known as “leaplings”. The chances of being a leapling are 1 in 1461 (365 x 4 + 1) and some of the most prominent include rappers Ja Rule and Saul Williams, actors Anthonio Sabato Jr. and Dennis Farina, Italian opera composer Gioacchino Rossini, big band leader Jimmy Dorsey, and my beautiful wife. Like Mr. Rule and her other co-leaplings, my partner eternal will be enjoying the ability to have a real birthday here in 2016. But what about the three years in between? When do Leap Year babies celebrate when there is no Leap Year, on February 28th or March 1st? Although most official sources like the DMV force someone born on Leap Day to wait until March 1st, in the eyes of my inside source, February 28th is the day, most specifically because she says “she’s born in February, not March”.

Leap Year Traditions

woman proposing - why do we have Leap Year?The most common of Leap Year traditions is making fun of our leapling friends for their age. Upon discovery of a leapling’s birthday, an almost automatic process of basic division begins to determine that our associate is 8 years old, say, rather than 32. It is a central plot point of Gilbert and Sullivan’s The Pirates of Penzance, wherein Frederic, who must serve the pirates until his 21st birthday, must serve four times as long because he was born on Leap Day. The other tradition tied to the February calendar addition is the reversal of the courtship social norm, allowing women to propose marriage to a man on this special day. Now, of course, here in 2016 there’s nothing actually preventing a woman from proposing on any day or year she chooses, but it remains less likely. So where did this tradition actually start? The best answer we can gather for this one is derived from rumor. The word is that in 5th century Ireland, St Brigid of Kildare asked St. Patrick to lift the ban on female marriage proposals, and he thus decreed that women could do so on February 29. In 1288, the tradition supposedly became law in Scotland with any man who declines required to pay a fine, such as a pair of gloves. Both cases are nearly impossible to substantiate, though, so this tradition’s origins remain sufficiently hidden from our knowledge.