Why is Friday 13th believed to be unlucky?

Hailey Heseltine ECB Publishing, Inc. If you go anywhere around the world, you will find superstitious traditions. Some say that you should knock on wood or throw salt over your shoulder for good luck, or that a broken mirror means seven years of bad luck. Superstition also goes beyond actions. There are even believed to be unlucky numbers, which translates to unlucky times and dates. For instance, in some East Asian countries, the number four is considered to be unlucky due to its similarity to the word for death in many languages. Because of this belief, a birth, marriage or other significant date occurring with the number four—day, month, or year—is avoided whenever possible. Wher