Look at the calendar. See Friday of this week? Yes, it is Friday the 13th.
I am not superstitious. Really, I am not. Well, maybe just a little…
The fear of Friday the 13th has been called friggatriskaidekaphobia. The word is derived from Frigga, the name of the Norse goddess for whom “Friday” is named in English, and triskaidekaphobia, meaning fear of the number thirteen.
Numerous stories abound as to the origins of the fear of Friday the 13th. However, Wikipedia claims “there is no written evidence for a “Friday the 13th” superstition before the 19th century. The earliest known documented reference in English occurs in Henry Sutherland Edwards’ 1869 biography of Gioachino Rossini, who died on a Friday 13th.
The most common reason that I have heard about the Friday the 13th superstition apparently stems from the fact that the Knights Templar were arrested on Friday, 13 October 1307. Many were tortured and eventually died. The story was popularized in Dan Brown’s 2003 novel The Da Vinci Code. However, historians claim that the “Friday the 13th” superstition was never mentioned in any books before the 19th century.
Friggatriskaidekaphobia is common mostly in English speaking countries. In Spanish-speaking countries, Tuesday the 13th (martes trece) is considered a day of bad luck. In Italian popular culture, Friday the 17th (and not the 13th) is considered a day of bad luck.
You can read more at http://en.wikipedia.org/wiki/Friday_the_13th.