The fear of the number 13 has been given a scientific name: "triskaidekaphobia"; and on analogy to this the fear of Friday the 13th is called paraskevidekatriaphobia, from the Greek words Paraskeví (Παρασκευή, meaning "Friday"), and dekatreís (δεκατρείς, meaning "thirteen").

The superstition surrounding this day may have arisen in the Middle Ages, "originating from the story of Jesus' last supper and crucifixion" in which there were 13 individuals present in the Upper Room on the 13th of Nisan Maundy Thursday, the night before his death on Good Friday.[3][4] While there is evidence of both Friday[5] and the number 13 being considered unlucky, there is no record of the two items being referred to as especially unlucky in conjunction before the 19th century. -Wikipedia에서

https://en.wikipedia.org/wiki/Friday_the_13th