Happy Friday the 13th!
Friday the 13th happens at least once in every year, sometimes twice (like this year). Last year there were three of them, which is the most we can possibly get.
Friday the 13th is considered by many to be an especially unlucky day. Read National Geographic’s “Friday the 13th Phobia Rooted in Ancient History.”
The number 13 doesn’t have to be unlucky. See “13 Lucky Facts About the Number 13” (PDF download).