Friday the 13th

The Writer's Almanac: "Today is Friday the 13th. The superstition that Friday is unlucky has been around for hundreds of years. Chaucer mentioned it in his Canterbury Tales, and by the 1800s, there was a whole list of things that were unlucky to do on a Friday, including needleworking, writing letters, beginning a sea voyage, moving, getting married, and going to the doctor. As for 13, its status as an unlucky number probably comes from the Bible — Judas Iscariot was said to be the 13th guest to sit at the table at the Last Supper. By the 1700s, it was a common superstition that if 13 people sat down at a table together, one of them would die. Eventually the number 13 became unlucky in any circumstance. Many hotels still skip the 13th floor, labeling it as 14. At some point, these two superstitions were combined into a fear of Friday the 13th."