Oh It's Friday 13th

Strangely, there is evidence to suggest that Friday the 13th is actually unlucky. Psychologists have found that some people are especially likely to have accidents or fall ill on Friday the 13th[citation needed]. This has been attributed to such people feeling a heightened state of anxiety on that day (see nocebo effect). The Stress Management Center and Phobia Institute in Asheville, North Carolina estimates that in the United States alone, $800 or $900 million is lost in business each Friday the 13th because people will not fly or do business they would normally do. [1]

The date is also well-known in the motorcycle (biker) community: since 1981, motorcycle enthusiasts and vendors gather every Friday the 13th in Port Dover, Ontario, Canada. This tradition started on November 13, 1981 by Chris Simons as a gathering of approximately 25 friends. The event has grown substantially, with an estimated 100,000 people attending in August 2004, as well as music bands, vendors, a bike show, etc.

In the Spanish-speaking world, it is Tuesday the 13th (as well as Tuesdays in general) that brings bad luck[citation needed]; a proverb runs En martes, ni te cases ni te embarques (on Tuesday, neither get married nor start a journey).