According to folklore, the superstition may have started from several sources.
Some people believe its roots are in numerology and that 12 is a 'complete number', making 13 unlucky.
This is based on the 12 hands on the clock, 12 signs of the zodiac and 12 apostles.
Friday is also considered to be unlucky and Black Friday is associated with market crashes.
It is thought Jesus died on a Friday and Eve supposedly tempted Adam with the forbidden fruit on a Friday.
Another Christian link dates back to the crusades. The Knights Templar, a military group which protected Christian pilgrims, was secretly ordered to be arrested on Friday October 13, 1307.
Historically a hangman's noose had 13 knots and 13 steps lead up to the gallows.
Today, the number is often missed out on house numbers and hotel floors. In France, it is considered to be 'poor form' to have 13 dinner guests at a party.
The fear of Friday the 13th is called paraskavedekatriaphobia and is thought to be an anxiety suffered by millions world wide.
I guess going to see Friday the 13th tonight is out of the question then, huh?