There was a transposition of numbers thanks to a drunken scribe. It was Friday, March 13, 1304 AD, Julian calendar, right after the cock crowed.
And that's how Friday the 13th got to be not a very good day.
Oh yeh, the drunken scribe ate the chicken. And the neighbor shot the drunken scribe because it was HIS chicken.
You want blasphemy, consider Bishop Usshers “precise” calculation that the first day of creation was Oct. 23, 4004 BC. He was so highly regarded that his figures were incorporated in the Bible, so apparently people believe that it was an original part of the Bible, and not a 16th Century clerics fun with numbers. See below:
http://www.lhup.edu/~dsimanek/ussher.htm