I went to an event that wasn't very thought out for the date. I looked it up, and apparently statistics show that a lot less accidents happen on Friday the 13th, because people are a lot more careful!
Also, I found out that the Navy (the real Navy) once decided to prove that Friday wasn't actually an unlucky day of the week. They made a ship called the HMS Friday, captained by Captain Friday, and finally set out on a Friday. They were never seen again.