Combining two unlucky elements into one day would make it all the more fearsome, and so it has become. One theory states that it is a modern amalgamation of two older superstitions: that thirteen is an unlucky number and that Friday is an unlucky day. Consequently, several theories have been proposed about the origin of the Friday the 13th superstition. Friday the 13th is thought to be a day of unlucky events, although the origins of such ideas are unclear. Some people are so paralyzed by paraskevidekatriaphobia that they avoid normal activities, and some refuse to travel on that day. The fear of Friday the 13th is called “paraskevidekatriaphobia,” a word derived from the Greek words Paraskeví (Friday) and dekatreís (thirteen), attached to phobia (fear).
Friday the 13th occurs from one to three times per year when the 13th day of any month falls on a Friday.
