Friggatriskaidekaphobia

Friggatriskaidekaphobia, (the fear of Friday the 13th) affects millions of people and costs Americans a billion dollars per year in absenteeism and costs businesses, especially airlines and train travel which suffer from severe losses on Friday the 13th. Triskaidekaphobia, or the fear of the number 13 is even more widespread. So much so that many high-rise buildings, hotels and hospitals skip the 13th floor and many airports do not have gates numbered 13. In many parts of the world, having 13 people at the dinner table is considered bad luck.