Fear of Friday the 13th is called Paraskavedekatriaphobia as well as Friggatiskaidekaphobia, however, if you have the fear of the number 13, then you suffer from Triskaidekaphobia. If you suffer from all three, I really feel sorry for you.
In fear of this day, many hospitals do not have a room 13, while some tall buildings will skip the 13th floor, and some airline terminals will omit Gate 13.
President Franklin D. Roosevelt would not travel on the 13th day of any month and would never host thirteen guests at a dinner.
There is also a popular belief that the reason the number 13 is unlucky is due to its position following the number 12. According to numerologists who consider the number 12 to be a complete number: there are 12 Months in a Year; 12 Signs of the Zodiac; 12 Gods of Olympus; 12 Labors of Hercules; 12 Tribes of Israel; 12 Apostles of Jesus; 12 Days of Christmas; and 12 Eggs in a dozen.
Since I do not suffer from Triskaidekaphobia, I have no problem stopping by the bakery and purchasing a Baker's Dozen of fresh, warm donuts. If I can then consume them before anybody catches me, then I consider myself lucky!
For those of you that work for a living, it might be a good day to take off from work. Just call your boss, supervisor, or anyone that cares and tell them that you will not be in for work today. Just tell them that due to your Triskaidekaphobia you are having an adverse reaction to your Paraskavedekatriaphobia and your Friggatiskaidekaphobia. By the time they figure it out, it will be Saturday the 14th and you will be enjoying a three day weekend. Who is going to argue with you?