IIt’s the first Friday the 13th of 2024, undoubtedly considered one of the unluckiest days of the calendar year. This year the date will occur twice, the next time in December. Friday the 13th is known as a day of bad luck, but how it got its “spooky” reputation goes back centuries, although an exact time frame is unclear.

The New York Historical Society says the origins can be traced in part to Jesus’ Last Supper. The story goes that 13 guests attended the Last Supper—Jesus Christ and his 12 apostles—and the following day, Good Friday, was the day of Jesus’ crucifixion.

This gave rise to a superstition among Christians that a table of 13 was “inviting death,” according to the New York Historical Society. The superstition was repeated in parts of Europe in the 1690s, with some believing it was bad luck to have 13 people around a table or in a group, according to the BBC.

Interestingly, the number 12 is often seen in Western cultures as a sign of ‘completion’ – the 12 apostles of Jesus, the 12 months of the year, the 12 signs of the Zodiac. The next number, however, is generally considered unlucky.

There are other deaths that some use to explain the unlucky day of the 13th. One example is the legend that more than 100 Templars were tortured and murdered by the French king Philip IV on Friday, October 13, 1307.

Fear of the number 13 even has its own name: triskaidekaphobia.

Friday the 13th isn’t an unlucky day everywhere in the world, though. In Spain, Tuesday the 13th is the day to fear, largely because of its connection to Mars, the Roman god of war and destruction, and in Italy, 17 is a number associated with fear because the Roman numeral XVII (17) can be rearranged into “VIXI,” which means “my life is over” in Latin, according to National Geographic.