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 are on the 13th. The 13th day of the month is slightly more likely to be a Friday than any other day of the week. On average, there is a Friday the 13th once every 212.35 days, whereas Thursday the 13th occurs only once every 213.59 days. In the 2010s there were three Friday the 13ths in 2012 and 2015, and two in 2013, 2017 and 2018. There will also be two in 2019 and 2020. In the 2020s, there will be three F13's in 2026, and two in 2020, 2023, 2024, and 2029. The rest of years have at