13: The Devil's Dozen
It is said: If 13 people sit down to dinner together, all will die within the year. The Turks so disliked the number 13 that it was practically expunged from their vocabulary (Brewer, 1894). Many cities do not have a 13th Street or a 13th Avenue. Many buildings don't have a 13th floor. If you have 13 letters in your name, you will have the devil's luck (Jack the Ripper, Charles Manson, Jeffrey Dahmer, Theodore Bundy and Albert De Salvo all have 13 letters in their names). There are 13 witches in a coven.
It is said: Never change your bed on Friday; it will bring bad dreams. Don't start a trip on Friday or you will have misfortune. If you cut your nails on Friday, you cut them for sorrow. Ships that set sail on a Friday will have bad luck – as in the tale of H.M.S. Friday ... One hundred years ago, the British government sought to quell once and for all the widespread superstition among seamen that setting sail on Fridays was unlucky. A special ship was commissioned, named "H.M.S. Friday." They laid her keel on a Friday, launched her on a Friday, selected her crew on a Friday and hired a man named Jim Friday to be her captain. To top it off, H.M.S. Friday embarked on her maiden voyage on a Friday, and was never seen or heard from again.