Friday 13th is a bad day to do somethings and I think that specify nearest Friday 13h is a funny exercise.
Design fastest algorithm to specify nearest Friday 13th with two directions - and +
example: current friday 13 is 13th October 2006.
nearest Friday 13th is 13th Junuary 2006 with direction -
rearest Friday 13h is 13th April 2007 with direction +