Friday the 13th has been described as a "pseudo-holiday" for some people. Any Friday that marks the 13th day of the month on the Gregorian calendar is known as "Friday the 13th."http://news.nationalgeographic.com/news/2010/08/100813-friday-the-13th-superstitions-triskaidekaphobia/ Many different superstitions surround Friday the 13th, with some believing it to be an unlucky day. According to some historians, superstitions about Friday the 13th can be traced back to Roman Times.http://news.nationalgeographic.com/news/2010/08/100813-friday-the-13th-superstitions-triskaidekaphobia/ While the term triskaidekaphobia (fear of the number 13) gets mentioned on Friday the 13th, the actual term psychologists use to describe people with a fear of Friday the 13th is "friggatriskaidekaphobia."http://www.cbsnews.com/8301-504763_162-20013574-10391704.html

Only one Friday the 13th was observed in 2010: Friday, August 13.http://news.nationalgeographic.com/news/2010/08/100813-friday-the-13th-superstitions-triskaidekaphobia/ In 2009, four different Friday the 13th's were observed. 2011 will bring just one Friday the 13th, but there will be four in 2012.http://www.huffingtonpost.com/2010/08/13/friday-the-13th-history-a_n_681152.html

If you are a sufferer of triskaidekaphobia, fear of the number 13, you may find yourself going out of your way to be extra careful on Friday the 13th. But did you know that there is a specific term for people afraid of Friday the 13th?

Superstitions surrounding Friday the 13th may actually date back to ancient times. Folklore historian Donald Dossey says superstitions and concerns surrounding Friday the 13th are dual. In Norse mythology, having more than 12 gods at a dinner party was considered bad luck. There are also Biblical references to the number 13. The apostle Judas was said to be the 13th guest at the Last Supper. Judas went on to betray Jesus. Some Christians associate Friday with bad luck because it marks the day that Jesus was crucified.http://news.nationalgeographic.com/news/2010/08/100813-friday-the-13th-superstitions-triskaidekaphobia/

Superstitions surrounding Friday the 13th have given way to pop culture. The popular Friday the 13th movie series began back in 1980. Since then, the series has spawned nearly a dozen additional films, all featuring unfortunate teenagers being stalked and murdered by masked killer Jason Voorhees on his birthday - Friday the 13th.http://www.imdb.com/title/tt0080761/