Friggatriskaidekaphobia - The Fear of Friday the 13th

Friday the 13th has been a day filled with tricks, pranks, suspicion for some for almost a thousand years. There are many stories about the origin of the date. For example, Wikipedia cites the following:

The superstition surrounding this day may have arisen in the Middle Ages, "originating from the story of Jesus' last supper and crucifixion" in which there were 13 individuals present in the Upper Room on the 13th of Nisan Maundy Thursday, the night before his death on Good Friday. While there is evidence of both Friday and the number 13 being considered unlucky, there is no record of the two items being referred to as especially unlucky in conjunction before the 19th century.

However, the more commonly held belief is the day was marked in black after on Friday, 13 October 1307, the date Philip IV of France arrested hundreds of the Knights Templar effectively stopping the order of Knights with those who weren't captured fleeing to other places across Europe with Scotland being the most popular destination according to legend.

Hear are more facts you might now have known about Friday the 13th:

1) Calenders

• In the 14 possible configurations for the annual calendar the occurrence of Friday the 13th is this:
  -- 6 of 14 years have one Fridays the 13th
  -- 6 of 14 years have two Fridays the 13th
  -- 2 of 14 years have three Fridays the 13th

No single year is without one Friday the 13th, and no year has more than 3.

2) Offices, Hospitals, Condos, Airports and Hotels
Many of these buildings will omit 13 from their floors on the elevator or remove that ominous number from airline gates out of respect for the suspicious.

Unrelated Fun Fact: Many elevators in hotels will program their elevators to skip floors if you press your desired floor (e.g. 7th floor) and also hold down the Close Door button at the same time. This is so room service attendants can swiftly move through floors without stopping if an employee-only elevator is not available.

3) Numbers
13 is also a member of the famous Fibonacci sequence, introduced in the 13th century. This sequence begins with zero and one, and the next number in the sequence is always the sum of the two preceding it, so we have 0+1=1,1+1=2, 1+2=3, 2+3=5, 3+5=8 and so on. If you want to know why rabbits breed so quickly, look no further than the Fibonacci sequence. Fibonacci is also responsible for introducing the decimal number system to Europe.

4) The Bible
Thirteen guests attended the Last Supper , according to biblical tradition, and the last to arrive was Judas, who betrayed Jesus. The next day was Good Friday, the day of Jesus' crucifixion.