Friday the 13th: What are the origins of the scariest day on the calendar?

Many folklore historians say it’s tough to pinpoint exactly how Friday the 13th came to be, and some believe it originates from the Last Supper, and the 13 guests who sat at the table on the day before the Friday on which Jesus was crucified.

“When those two events come together, you are reenacting at least a portion of that terrible event,” Dr. Phil Stevens an associate professor of anthropology at the University at Buffalo, told TIME. “You are reestablishing two things that were connected to that terrible event.”

The Thirteen Club

Well over 100 hundred years ago, in the late 19th century, a New Yorker named Captain William Fowler sought to remove the enduring stigma surrounding the number 13 and particularly the unwritten rule about not having 13 guests at a dinner table by founding an exclusive society called the Thirteen Club.

The group ate regularly on the 13th day of the month in room 13 of the Knickerbocker Cottage, a popular watering hole Fowler owned. Before sitting down for a 13-course dinner, members would pass beneath a ladder and a banner reading “Morituri te Salutamus,” Latin for “Those of us who are about to die salute you.”

Convenient milestone

Most theories may exist in an attempt to explain the unexplainable, according to Dr. Simon Bronner, a professor of American studies and folklore at Pennsylvania State University. To him, Friday the 13th is just a convenient milestone for people who are looking to trace bad luck to a certain cause but there’s nothing special about the date itself. After all, the number 13 is apparently considered lucky some countries, like Italy, Bronner adds.

Four former US presidents (Chester A. Arthur, Grover Cleveland, Benjamin Harrison and Theodore Roosevelt) would join the Thirteen Club’s ranks at one time or another.

Pop culture

An important milestone in the history of the Friday the 13th legend in particular (not just the number 13) occurred in 1907, with the publication of the novel Friday, the Thirteenth, written by Thomas William Lawson. The book told the story of a New York City stockbroker who plays on superstitions about the date to create chaos on Wall Street, and make a killing on the market.

The horror movie Friday the 13th, released in 1980, introduced the world to a hockey mask-wearing killer named Jason, and is the best-known example of the famous superstition in pop culture history. The movie spawned multiple sequels, as well as comic books, novellas, video games and countless terrifying Halloween costumes.

Why Friday?

The negative association with Friday specifically has a combination of cultural and religious origins. Many Christians believe Friday to be unlucky because it was the day of the week that Jesus was crucified on. In the 14th and 15th centuries, prominent figures started to publicly denounce the day with little context as to why. Playwright Robert Greene defined “Friday-face” as “a sad look of dismay or anguish and George Chaucer’s Canterbury Tales depicts Friday to be “a day of misfortune”.