Paraskavedekatriaphobian- Person who has a Fear of Friday the 13th .
I disagree with Terry , friday the 13th , unlucky for some , comes from 1307 when the church ordered the executions and hunting down of the Knights Templar,
During the Middle Ages, the superstition against Friday the 13th grew. On Friday, October 13, 1307, King Philip IV of France ordered the arrests of Jaques de Molay, Grand Master of the Knights Templars and sixty of his senior knights in Paris. Thousands of others were arrested elsewhere in the country. After employing torture techniques to compel the Templars to "confess" to wrongdoing, most were eventually executed and sympathizers of the Templars condemned Friday the 13th as an evil day. Over time a large body of literature and folk wisdom have reinforced the belief. In the 18th century, the HMS Friday was launched on Friday the 13th. It was never heard from again. Since then, ships are not usually launched on that date. (Click here for other mysterious ship disappearances.)