If you suffer from friggatriskaidekaphobia, otherwise known as paraskevidekatriaphobia, today is not your lucky day.

Friggatriskaidekaphobia is the fear of Friday the 13th. The Stress Management Center and Phobia Institute of North Carolina estimates the fear of Friday the 13th affects between 17 and 21 million Americans and that $800 or $900 million is lost in business on this day because people will not fly or do business they would normally do.

While the history on exactly where the Friday the 13th superstition comes from is a bit sketchy, there are plenty of theories (such as linking it to Friday, Oct. 13, 1307, and the “demise” of the Knights Templar).

The unfortunate combination of an unlucky day and an unlucky number is enough for many people, and many Friday the 13th superstition round-ups point to the same “reasons.”

Friday
Friday is said to be the day that Eve offered Adam the forbidden fruit and Jesus was crucified.

A sailor will tell you to never begin a voyage on Friday.

There is a long list of ‘what not to do’s’ on Fridays. For example, it is advised to never change your bed on a Friday for it may bring bad dreams.

13
There is the concept that the number 12 signifies completeness (12 zodiac signs, 12 months in a year, 12 hours on the clock, etc.) and that the number 13 goes against this.

Or the belief that if you have 13 letters in your name, you are linked with the devil (example, Charles Manson).
Then there are the reports of hospitals and hotels omitting rooms with the #13, cities that don’t have a 13th street or avenue, and airports with no gate 13 or planes with no aisle 13. I read one statistic that more than 80% of skyscrapers lack a 13th floor.

As a last example, there is the superstition that having 13 people at a table will result in the death of one of the diners, some say within a year. This superstition is tied to both the Last Supper and a Norse Myth where the evil god Loki crashed a dinner party for 12 at Valhalla, great hall of the gods, and proceeded to trick another guest into killing Balder the god of light.

Poor number 13’s reputation is so tarnished, some have rallied to debunk the stigma as far back as 1881. Captain William Fowler, a Civil War veteran, formed a dinner club with friends and called it the Thirteen Club. They had their first meeting on Friday, the 13th of January at 8:13pm. There were 13 guests. They further tempted fate by entering the room walking under a ladder and had piles of spilled salt at their tables. All the guests survived the next 12 months. Thirteen Clubs went on over the years to become quite popular and members included five men who would go on to be Presidents, including Theodore Roosevelt. I’m thinking of reviving a modern day Thirteen club myself just to have an excuse for a dinner party.

Friday the 13th is unavoidable, with one occurring every year. And some years, as a matter of fact this year, there are more. 2012 brings us three Friday the 13th’s (January, April, July). Good things happen in threes, right? Or is it bad things… I forget.