Triscadecaphobia is the fear of the number 13.  Many believe Friday the 13th is especially a very unlucky day.  

In Ancient Rome, the citizens dedicated the 6th day of the week to their beautiful Goddess Venus.  Eventually this day evolved into Friday, and was considered to be the luckiest day of the week.

Muslims claim Friday as the day Allah created Adam, legend has it that Adam and Eve ate the forbidden fruit on a Friday, and later died on a Friday.

Christians consider Friday as the day on which Christ was crucified by the Romans. The Last Supper was Jesus said goodbye to his apostles before being crucified.  How many were at the table? 14, including Judas.

Next up was Friday, October 13, 1307.  The Pope of the church in Rome in Conjunction with the King of France, carried out a secret death warrant Against "the Knights Templar". The Templars were terminated as heretics, never again to hold the power that they had held for so long. There Grand Master, Jacques DeMolay, was arrested and before he was killed, was tortured and crucified.

The Scandinavians believe that the number 13 signified bad luck came from their mythological 12 demigods, who were joined by a 13th demigod, Loki, an evil cruel one, who brought upon humans great misfortune.

So, there are a great number of reasons why many around the globe find Friday the 13th a day, if not unlucky, a day to take notice and caution.

Required Reading for Italian-Americans...