Friggatriskaidekaphobia or paraskevidekatriaphobia = fear of Friday the 13th.
I've never been very superstitious about Friday the 13th (probably because it's too hard to pronounce), but it's always something that's in the back of my mind. This year, we will have the maximum possible number of Friday the 13ths in a calendar year (three). They will occur in January, April, and July. Then we're clear straight through to September 2013!
Historically, there is no written evidence of the Friday the 13th superstition before the 19th century (see this Wikipedia article). I wondered whether any of my ancestors were superstitious about the date. Since they aren't around to ask anymore, I decided to see how many people in my family tree were born or died on Friday the 13th. I was surprised that no one in my tree died on Friday the 13th. No one was married on Friday the 13th (which may be a clue to the superstitious nature of my people, but it could also be that Catholics don't typically marry on Fridays), and only 3 were born on Friday the 13th:
Marie-Josephte Bruneau - born 13 Jul 1744 in Quebec, Canada. She is the wife of my 5th great granduncle, Pierre Joseph Lanctot. She lived to be 81 years old.
Josiah Bell - born 13 Nov 1807 in Surry, Virginia. He is my 7th great granduncle. He lived to be 88 years old.
Bessie Ruth Mount - born 13 Dec 1912 in Scottsburg, Indiana. She is my half 3rd cousin 3x removed. She lived to be 86 years old.
Looks like Friday the 13th wasn't a big deal in my family. They probably couldn't pronounce it either.