friday 13th
Friday the 13th is synonymous with bad luck or getting hacked to pieces at sleep-away camp by a hockey mask wearing psychopath named Jason...which it turns out would be pretty unlucky. The origin of the superstition dates back only to the 19th century and is likely a combination of two perceived omens of bad luck - Friday, and the number 13. The phobia of Friday the 13th is known as friggatriskaidekaphobia and is characterized by an extreme aversion to people named Jason, particularly if they are carrying a chefs knife and going on and on about how wonderful Camp Crystal Lake is.