Thirteen Facts About Friday the 13th

Today is Friday the 13th, and if you’re very superstitious you’ll probably be looking over your shoulder all day, hoping to avoid any bad luck. If you’re not superstitious, well, today may only prompt an indifferent shrug. Either way, here are 13 facts you may not have known about this unluckiest of days.

1. Frequency: Friday the 13th occurs at least once a year, and as many as 3 times a year. Today is the last one until June 13, 2014.

2. The fear of the number 13 is called Triskaidekaphobia, and the fear of Friday the 13th is known as Paraskevidekatriaphobia.

3. An estimated 17 to 21 million people in the United States are affected by Paraskevidekatriaphobia, making it the most feared day and date in history.

4. President Franklin D. Roosevelt apparently suffered from triskaidekaphobia. He refused to travel on the 13th day of any month and would not host a dinner party with 13 guests.

5. Friday has been considered an unlucky day at least since the 14th century's The Canterbury Tales, and many other professions have regarded Friday as an unlucky day to undertake journeys or begin new projects.

6. There is also a superstition, thought by some to derive from the Last Supper or a Norse myth, that having 13 people seated at a table results in the death of one of the diners.

7. Bad luck at the Stock Exchange: the mini crash of Friday, Oct. 13, 1989 was the second largest drop of the Dow history.

8. NASA was almost tragically unlucky with its Apollo 13 mission. The capsule was launched at 13:13 on April 11, 1970. The explosion that ultimately destroyed the craft took place on April 13th.

9. People in Spanish speaking countries consider Tuesday (not Friday) the 13th to be unlucky.

10. In Italian popular culture, Friday the 17th (not the 13th) is considered a day of bad luck. In fact, in Italy, 13 is generally considered a lucky number.

11. The ancient Chinese regarded the number 13 as lucky. The ancient Egyptians also thought 13 brought good luck.

12. According to a recent Washington Post report, the risk of being in a car crash on any Friday is higher than other days of the week. Police attribute this fact to alcohol consumption.

13. To avoid bad luck on Friday the 13th: touch wood, cross your fingers, avoid black cats, don't look at the full moon through a pane of glass, and throw salt over each shoulder.