Friday the 13th is considered an unlucky day. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday, which happens at least once every year but can occur up to three times in the same year. In 2017, it occurred twice, on January 13 and October 13. In 2018, it will also occur twice on April 13 and July 13. There will be two Friday the 13ths every year until 2020, where 2021 and 2022 will have just one occurrence, in August and May respectively.
Friday the 13th is an American horror franchise that comprises twelve slasher films, a television show, novels, comic books, video games, and tie‑in merchandise, as of 2017. The franchise mainly focuses on the fictional character Jason Voorhees, who drowned as a boy at Camp Crystal Lake due to the negligence of the camp staff. Decades later, the lake is rumored to be “cursed” and is the setting for a series of mass murders. Jason is featured in all of the films, as either the killer or the motivation for the killings. The original film was written by Victor Miller and was produced and directed by Sean S. Cunningham. The films have grossed over $464 million at the box-office worldwide.