Updated December 13, 2024 at 13:54 PM ET
The superstition that Friday the 13th is an unlucky day has been around for the past 100 years. But it doesn't have the ancient origins that many might expect.
It's hard to pinpoint exactly why Friday the 13th is considered an unlucky day. Experts can only speculate.
"The United States, we get it from England… it wasn't considered an unlucky day in England until the 20th century. The first recorded instance we have of that in print is 1913," said Moira Marsh, a folklore librarian at the University of Indiana Bloomington.
"People start to make references to it being unlucky without saying why they think it's unlucky. And because of that, typically what you get is all kinds of wild theories about why Friday the 13th is unlucky," said Stephen Winick, a folklore specialist at the American Folklife Center of The Library of Congress.
Some reasons why Friday the 13th is thought to be unlucky
Some speculate that Friday the 13th is unlucky because Judas was the 13th guest at the Last Supper, or that Knights Templar were condemned on a Friday the 13th. But Winick said experts don't know if any of those things are true.
The first references Winick has seen saying Friday the 13th is unlucky are both from French writing and plays.
A character in the 1834 play Les Finesses des Gribouilles says "I was born on a Friday, December 13th, 1813 from which come all of my misfortunes." And in the French literary magazine Revue de Paris, Marquis de Salvo wrote about a father who killed his daughter on Friday the 13th, and said "It is always Fridays and the number thirteen that bring back luck."
While the combination of Friday and 13 is a relatively new invention, the idea that Fridays are unlucky is not.
"Fridays were considered unlucky days, and that's been true since the Middle Ages in the English speaking world and probably through most of Europe, because Friday was the day of crucifixion. And in the old Catholic tradition, every Friday was a day of penance. And that idea has persisted," said Marsh.
Marsh said the idea that 13 is an unlucky number doesn't really show up until around the 17th century.
"Before that, it might have been considered a good number because it goes back to supposedly the 13 people who were at the Last Supper. Before reformation, Christians preferred to try and emulate that."
After the Reformation came along, Marsh said ideas like that were forbidden as superstitious. And so what was considered a good number flipped to be considered a bad one.
There's another idea about why the number 13 is unlucky.
"12 is a number that's very mathematically significant. It's divisible by many different numbers. And it's very useful mathematically for various things," said Winick. There are 12 months, 12 zodiac signs, 12 inches in a foot. "And then 13 comes along and it's kind of a dud. It doesn't really help you out much mathematically."
Unlucky days in other countries
Marsh and Winick say that thanks to popular culture, like the movie Friday the 13th, the day is now pretty widespread in countries around the world. And journalists have had a hand in spreading the popularity of that idea.
In Italy, Winick said, the unlucky day tends to be Friday the 17th. And then in Spanish speaking countries, the unlucky day tends to be Tuesday the 13th.
"People speculate that's because Tuesday is associated with the chaotic God of war. You know, Martes or Tuesday in Spanish is related to the God of war, Mars. Because of that, people think that may be the origin of Tuesday's being unlucky," said Winick.
Marsh said a Greek nurse in the 1960s may be another source who found Tuesdays to be unlucky. According to this nurse, if a wedding ended on a Monday evening, the women of the family would keep the bridge close by so that her husband wouldn't touch her. Because if any child was conceived on a Monday evening, the beginning of Tuesday would be considered unlucky, and the baby would likely have birth defects.
In Greece, Winick said they often link the potential origins back to ancient Greek culture. So they'll think about ancient Greek mathematics, which had ideas that the number 12 was a good number, and 13 was a bad number.
"We seek explanations for the chaotic experience of life. We want to explain to ourselves why things have happened in a certain way, why things didn't go our way… it gives us a sense of control even though we may not have control," said Winick.
Editor's note: This story originally published Sept. 13, 2024.
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