Last century, there were 7 full moons that fell on Friday the 13th on the east coast of North America.

Friday, March 13, 1903
Friday, October 13, 1905
Friday, June 13, 1919
Friday, January 13, 1922
Friday, November 13, 1970
Friday, February 13, 1987
Friday, October 13, 2000

What else was needed? Killing the rabbit in a graveyard or some such?

(by the way, the next one is September 13, 2019)