Paraskevidekatriaphobia

fear of Friday the 13th:

...""The sixth day of the week and the number 13 both have foreboding reputations said to date from ancient times, and their inevitable conjunction from one to three times a year (there happens to be only one such occurrence in 2011, in the month of May) portends more misfortune than some credulous minds can bear. According to some sources it's the most widespread superstition in the United States today. Some people refuse to go to work on Friday the 13th; some won't eat in restaurants; many wouldn't think of setting a wedding on the date.

How many Americans at the beginning of the 21st century suffer from this condition? According to Dr. Donald Dossey, a psychotherapist specializing in the treatment of phobias (and coiner of the term paraskevidekatriaphobia, also spelled paraskavedekatriaphobia), the figure may be as high as 21 million. If he's right, no fewer than eight percent of Americans remain in the grips of a very old superstition. ...""

In the words of Penn Jillette...bull-shit.

for a conservative Christian viewpoint on Friday the 13th: click-a-nate