Today is Friday the 13th :). Reminded me immediately of the movie Friday the 13th. Also reminded me of a common belief, that Friday the 13th is associated with badluck. So I went into wikipedia.org and looked up Friday the 13th. This is what I found-
"The fear of Friday the 13th is called paraskevidekatriaphobia, a word derived from the concatenation of the Greek words Paraskeví (Παρασκευή) (meaning Friday), and dekatreís (δεκατρείς) (meaning thirteen), attached to phobía (φοβία) (meaning fear). The term triskaidekaphobia derives from the Greek words "tris", meaning 'three', "kai", meaning 'and', and "deka", meaning 'ten'. the whole word means three and ten. "