02/29/2024
LEAP YEAR FACTS:
Numbers, history, and lore exist to keep the months in sync with annual events, including equinoxes and solstices
It’s a correction to counter the fact that Earth’s orbit isn’t precisely 365 days a year. It takes about six hours longer than that.
Not every four years is a leap year. Adding a leap day every four years would make the calendar longer by more than 44 minutes. And thus, it was decreed that years divisible by 100 not follow the four-year leap day rule unless they are also divisible by 400.
In the past 500 years, there was no leap day in 1700, 1800 and 1900, but 2000 had one. In the next 500 years, if the practice is followed, there will be no leap day in 2100, 2200, 2300, and 2500.
The next leap years are 2028, 2032 and 2036.
Eventually, without leap yeara, major events like when farmers plant and how seasons align with the sun and the moon would get out of whack. In a few hundred years we would have summer in November. Christmas will be in summer.
Ancient civilizations used the cosmos to plan their lives, and there are calendars dating back to the Bronze Age. They were based on either the phases of the moon or the sun, as various calendars are today. Usually, they were “lunisolar,” using both.
The Roman Empire under Julius Caesar was dealing with major seasonal drift and introduced his Julian calendar in 46 BCE. It was purely solar and counted a year at 365.25 days, so once every four years an extra day was added.
But there was still drift because there were too many leap years! The solar year isn’t precisely 365.25 days! It’s 365.242 days.
The Julian calendar was 0.0078 days (11 minutes and 14 seconds) longer than the tropical year, so errors in timekeeping still gradually accumulated.The Julian calendar was the model used by the Western world for hundreds of years.
Enter Pope Gregory XIII, who calibrated further. His Gregorian calendar took effect in the late 16th century. It remains in use today and isn’t perfect or there would be no need for leap year. But it was a big improvement, reducing drift to mere seconds.
The Pope stepped in because Easter was coming later in the year over time, and he fretted that events related to Easter like the Pentecost might bump up against pagan festivals. The pope wanted Easter to remain in the spring.
It’s Pope Gregory and his advisers who came up with the really gnarly math on when there should or shouldn’t be a leap year.
If the solar year was a perfect 365.25 then we wouldn’t have to worry about the tricky math involved.
Bizarrely, leap day comes with lore about women popping the marriage question to men. It was mostly benign fun, but it came with a bite that reinforced gender roles.
European folklore places the idea of women proposing in fifth-century Ireland, with St. Bridget appealing to St. Patrick to offer women the chance to ask men to marry them.
Nobody really knows where it all began.
In 1904, syndicated columnist Elizabeth Meriwether Gilmer, aka Dorothy Dix, summed up the tradition this way: “Of course, people will say ... that a woman’s leap year prerogative, like most of her liberties, is merely a glittering mockery.
The pre-Sadie Hawkins tradition merely perpetuated stereotypes. The proposals were to happen via postcard, but many such cards turned the tables and poked fun at women instead.
Advertising perpetuated the leap-year marriage game. A 1916 ad by the American Industrial Bank and Trust Co. read thusly: “This being Leap Year day, we suggest to every girl that she propose to her father to open a savings account in her name in our own bank.”
There was no breath of independence for women due to leap day.
Being born in a leap year on a leap day certainly is a talking point, but it can be a a paperwork pain. Some government forms declared what date was used by leaplings for such things as driver's licenses, whether Feb. 28 or March 1.
Technology has made it far easier for leap babies to jot down their Feb. 29 milestones, though there can be glitches in terms of health systems, insurance policies and with other businesses and organizations that don’t have that date built in.
There are about 5 million people worldwide who share the leap birthday out of about 8 billion people on the planet.