Friday the 13th is widely known as an unlucky day. The date even inspired a series of 12 successful horror movies. The exact origin of the superstitious date is hard to pin down, but here’s a list of 13 facts about Friday the 13th:

Today will be the only Friday the 13th in the year 2016. Some historians believe the date came from the number of guests at Jesus’s last supper on Holy Thursday. Other historians note that the origin could stem from Friday, October 13, 1307, when Philip IV of France arrested hundreds of the Knights Templar. Geoffrey Chaucer wrote on the unluckiness of the day in his Canterbury Tales stating that it was bad luck to start a journey or a project on a Friday.  In the Da Vinci Code, Dan Brown references the 14th century execution of Templar Grand Master Jacques de Molay, which happened on Friday the 13th. A study published in the British Medical Journal found that hospital admissions for traffic accidents were 52 percent higher on Friday the 13th than Friday the 6th. The fear of Friday the 13th is called paraskevidekatriaphobia from the Greek words paraskeví (meaning 'Friday') and dekatreís (meaning 'thirteen'). The fear of the number 13 itself is called triskaidekaphobia. Donald Dossey, founder of the Stress Management Center and Phobia Institute, said that U.S. businesses lose an estimated $800 to $900 million on Friday the 13th because people will not fly or conduct business as they normally do. The master of suspense, Alfred Hitchcock was born on August 13, 1899. Friday, August 13, 1999 would have been his 100th birthday. Taylor Swift turned 13 on Friday the 13th, which is one of many reasons she says 13 is her lucky number. Since 1995, Finland has dedicated one Friday the 13th a year to observe National Accident Day. In Britain, some believe they should only cut hair and nails on certain days and cutting them on Friday is thought of as a path to misfortune. In fact, many couples will refrain from marrying on a Friday.