Friday 13 is considered an unlucky day in Western superstition. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday. 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 people present in the Upper Room on Maundy Thursday, the night before His death on Good Friday. However there is no written evidence for a "Friday 13" superstition before the 19th century. Touch and hold one date to copy entire list into clipboard.