Laura Dean Bennett
The concept of Leap Year, how it came about and why, is way more complicated than one might think.
After reading extensively about it, I can barely grasp all of the intricacies of how is it calculated.
It’s an on-going mathematical algorithmic process which, it seems to me, is strictly for those who enjoy higher math.
But the ancient Babylonians, Egyptians and Romans grasped it quite well.
This Saturday is February 29.
It’s an unremarkable date except that it only shows up on the calendar about once every four years.
There are 97 leap years every 400 years on the Gregorian calendar, and 2020 happens to be one.
The Gregorian calendar, which is used nearly universally across the world now, came into common usage in the 16th century, when Pope Gregory XIII introduced it.
It has “common” years which contain 365 days and “leap” years which contain 366 days. The extra day is always designated as February 29.
The actual time it takes for the earth to orbit the Sun is 365.24219878 days.
So, using a 365 day calendar, over time, our calendar and the astronomical calendar fall out of step.
Humans have been trying to compensate for this discrepancy ever since there have been calendars.
The oldest Babylonian calendar consisted of 12 months, based on the cycles of the moon.
But, featuring 354 days per year, it fell a fair number of days short of the astronomical year.
The ancient Egyptians brought this calendar up to 360 days.
To keep the seasons straight, they eventually added five days at the end of each year.
More than 3,000 years later, in 238 B.C., the Egyptian king Ptolemy III introduced a sixth day at the end of every fourth year – which was technically the original leap year.
Julius Caesar noticed this and included it when he reformed the existing Roman calendar, except he added the extra day to February in his new Julian calendar.
But adding an extra day every four years didn’t entirely solve the problem.
The remaining discrepancy was almost insignificant, showing up only as the calendar and the seasons gradually fell out of sync over the course of centuries, when a one-day error per every hundred years could be noticed.
This may not seem like a lot, but over the course of centuries it added up.
By the 16th century, the vernal equinox was falling around March 11 instead of where it astronomically should – on March 21.
But it took more than 500 years before an official calendar change could be made.
In 1582, Pope Gregory XIII, in consultation with his astronomers, decreed that a calendar adjustment was needed.
October would lose 10 days, meaning that October 4, 1582, would be immediately followed by October 15.
Pope Gregory also twea-ked the leap-year cycle to address the remaining one-day- per century drift.
A century year could be a leap year unless it was exactly divisible by 400 – which is why 1600 and 2000 were leap years, while 1700, 1800 and 1900 were not.
The new “century rule” was the sole feature distinguishing the new Gregorian calendar from the old Julian calendar.
Protestants rejected the Catholic Church’s calendar adjustment until 1752, when Great Britain and its colonies adjusted its calendar by having September 2 be followed by September 14.
But Pope Gregory’s calendar – maybe because of slightly imprecise astronomical calculations – resulted in an extra 26 seconds each year, resulting in an error of a full day every 3,320 years.
That tiny error remains in the Gregorian calendar, and to correct for most of it, our descendants will have to cancel Leap Year every 3,200 years.
Accurately calculating Leap Years is seemingly infinitely complicated – because Earth’s orbital speed isn’t precisely constant.
This means that, occasionally, “leap seconds” need to be added to our clocks to keep them accurate.
But enough with the math.
Let’s move on to Leap Year sociology.
Those born on Leap Day are called Leaplings.
There are about 187,000 of them in the U.S. and four million Leaplings in the world.
For those born on February 29, each state decides whether or not February 28 or March 1 will be the day they are eligible to get their driver’s license.
For driver’s license purposes, most states consider March 1 as a Leapling’s official birthday.
The odds of being born on Leap Day are one in 1,461.
Irish legend says that Saint Brigid of Kildare asked Saint Patrick to allow women to propose to men because, as the story goes, Saint Brigid insisted that some male suitors were too timid, making women wait too long for them to propose.
It’s said that Saint Patrick allowed women to take the initiative and propose every seven years.
But Saint Brigid finally convinced him to agree to allow women to propose every four years – on Leap Day.
There’s a tall tale about Saint Patrick and Saint Brigid that says that as soon as he agreed to a woman proposing, Saint Brigid fell onto one knee and proposed to him – but Patrick declined – and he gave her a kiss on the cheek and a silk gown as recompense.
There are still those in Ireland who enjoy spoofing about women proposing to men on Leap Day.
The Irish call Leap Day “Bachelor’s Day,” and there are parties and festivals which celebrate it.
The Leap Day proposal tradition was taken to Scotland by Irish monks where it found fertile ground.
In 1288, the Scottish Queen Margaret (who may have been only five years old at the time) passed a law that allowed a woman to propose marriage on Leap Day, and that any woman proposing must wear a red petticoat while doing so.
Should the gentleman refuse, a fine would be imposed.
It could range from a kiss to a silk gown, to a pair or 12 pairs of gloves or money.
Finland also has a tradition about a man who refuses the proposal of a lady on Leap Day.
He must pay a fine sufficient to the price of enough fabric to make a skirt.
In Denmark, legend has it that if you refuse such a proposal you must present gloves to the lady to hide her ringless finger.
In places around the United States, February 29 is known as Sadie Hawkins’ Day.
Sadie Hawkins was a female character in the legendary Al Capp comic strip, “Li’l Abner,” who inspired Sadie Hawkins Dances – an event allowing girls to invite boys to a dance.
For ladies considering making a Leap Day proposal who don’t yet have a particular groom in mind, you have a little time to get organized.
The next Leap Day will be February 29, 2024.