SPRINGFIELD, Mo. – May 13, 2022, is a Friday, and many countries around the world consider this date unlucky. But what is the real story behind Friday the 13th?

According to history.com, Western cultures associate the number 12 with completeness—12 days of Christmas, 12 months and zodiac signs, 12 labors of Hercules, 12 gods of Olympus and 12 tribes of Israel— it’s uncertain exactly when this particular tradition began, however, negative superstitions around the number 13 have been around for centuries.

It’s estimated that as many as 10 percent of the U.S. population has a fear of the number 13, and the even more specific fear of Friday the 13th, known as paraskevidekatriaphobia, has resulted in financial losses in excess of $800 million annually.

People will also avoid getting married, traveling or even working in severe cases of paraskevidekatriaphobia.

According to the Stress Management Center and Phobia Institute in Asheville, North Carolina, more than 80 percent of hi-rise buildings in the United States do not have a 13th floor, and the vast majority of hotels, hospitals and airports avoid using the number for rooms and gates as well.

But 13 might only be unlucky to Westerners. Some cultures like the Ancient Egyptians considered the number lucky, while the number 4 is considered unlucky in much of Asia.

The exact reason why Friday is included in the bad luck date is also unclear. Some might suggest it has roots in Christian traditions: Just as Jesus was crucified on a Friday, Friday was also said to be the day Eve gave Adam the fateful apple from the Tree of Knowledge, as well as the day Cain killed his brother, Abel.

Here’s livescience.com’s list of ‘Freaky things that happened on Friday the 13th.”