It's Friday The 13th . . . . . Again!

When the 13th day of the month falls on a Friday, it seems to generate an irrational fear in some people. While during most years the two coincide once or at the most twice, this year we have had the misfortune of having three of them. First on January 13th, then April 13th and the Grande Finale, which happens to be today, Friday July 13th! Another odd coincidence this year is the trio are exactly 13 weeks apart - Something that hasn't happened, since 1984.

While most of us shrug it off as just another day, for about 20 million Americans and many others worldwide, this is a day to be feared. In fact that phobia is so real that it has even been designated two rather long names - friggatriskaidekaphobiac and paraskevidekatriaphobia. To make matters worse, within this group is a subset of people called Triskaidekaphobiacs that are simply afraid of the number 13 and try avoid it at all costs.

So who are all this people? Not surprisingly, many work in professions like construction and ship building, where they are subject to injury risks on a day-to-day basis. But what is quite astonishing is that the fear extends to white-collar workers like stock brokers and even, presidents.

Legend has it that former US President Franklin D. Roosevelt feared the date so much that he never traveled on the 13th nor invited just 13 guests to a meal. Even American author and humorist Mark Twain began believing in the power of the date, after he was left hungry as the 13th guest at a party that had catered food for only 12. So strong is the superstition in Paris that diners wishing to avoid bad luck can hire a quatorzieme or professional 14th guest.

So how did this date and day of the week acquire such a bad reputation? While nobody knows for sure, here are a few theories. According to Donald Dorsey, a folklore historian, the fear of the number can be traced all the way back to ancient times, when the Vikings inhabited Scandinavia.

According to the legend, twelve gods were having a dinner party at Valhalla, the Viking's mythological heaven. Suddenly, an uninvited guest, the mischievous god Loki walked in and instigated Hoder, the blind god of darkness to shoot Balder, the god of joy and gladness.

Friday being unlucky is also rooted in ancient mythology and religion - According to the bible, Jesus was crucified on a Friday. Though the date is not believed to be the 13th, it was following the Last Supper, which happened to be attended by 13 men that included Judas Iscariot, the apostle that betrayed Jesus. Other biblical scholars maintain that this was the day when Eve tempted Adam with the forbidden fruit - Again, the date is a little hazy. The one bad event that is believed to have happened on Friday the 13th, was the slaying of Abel by his brother Cain (The sons of Adam and Eve).

For those looking for modern day evidence, there are the various unexpected mishaps experienced by the astronauts aboard the Apollo 13 spacecraft. Besides being tagged with the dreaded number, it was also the 13th in a series of missions using Apollo specification flight hardware. The good news of course is though the astronauts had to abandon the lunar landing, they did return to Earth safely.

A more recent tragedy was the sinking of the cruise ship Costa Concordia on Friday, January 13th, 2012.

Of course, to most of us this is all just a coincidence and the only reason we give the date any credence is because the events happen to occur on this so-called dreaded day. But for many, the fear is quite real. Experts estimate that businesses lose between $800-$900mm USD on this day because millions of people avoid traveling, going to work and even, shopping!

Do you believe that there is something sinister about the 13th especially, when it falls on a Friday? If so, be sure to add your comments below.

Resources: shorenewstoday.com, urbanlegends.about.com, nationalgeographic.com, vancouversun.com, livescience.com, philly,com