Friday the 13th one occurrence each. A Friday the 13th occurs during any month that begins on a Sunday. 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
Friday the 13th the last two years, Dutch insurers received reports of an average 7,800 traffic accidents each Friday; but the average figure when the 13th fell on a Friday was just 7,500." In years which begin on the same day of the week and are of the same type (that is, whether they are a common year or leap year), Friday the 13th occurs in the same months. This sequence, given here for 1900–2099, follows a 28-year cycle from 1 March 1900 to 28 February 2100. The months with a Friday the 13th are determined by the Dominical letter (G, F, GF,