LAS VEGAS (KLAS) — Some think nothing of it while others fear it — Friday the 13th. For the superstitious, the number 13 can mean misfortune or bad luck, but add it to a Friday and it suddenly becomes elevated and has a name so long, you might be more fearful of trying to pronounce it than the date itself.

Paraskevidekatriaphobia is the fear of Friday the 13th and the term was first used a century ago.

This year, there will be two such Fridays. The first is today and the second is in October. There is at least one Friday the 13th every year and some years have as many as three.

There are various theories why the date is considered unlucky including that it began with the Last Supper because Judas Iscariot was the 13th guest to arrive and he was the person who betrayed Jesus. The following day, Friday was the day of Christ’s crucifixion. According to History.com, another belief is that Friday, October 13, 1307, spelled doom for the Knights of Templar.

The fear can even be found in pop culture. A popular series of horror movies started when “Friday the 13th” was released in 1980.

The fear of the number 13 primarily exists in Western culture and that’s why you will find hotels with no 13th floor, dinner parties without a 13th guest, and people avoiding the date for special occasions such as weddings.

Ancient Egyptians considered 13 to be a lucky number. In today’s world, people from Italy and China believe 13 is lucky.