Hard-hats at the ready – it's Friday the 13th. For the third time this year!

According to how the calendar falls there will be two Friday the 13th's next year (in September and December), one in 2014 and three in 2015. After that there won't be another three until 2026. Make of that what you will.

Fear of this date is known as friggatriskaidekaphobia (named after "Frigg", the Norse goddess whom Friday is named after and "triskaidekaphobia" meaning the fear of "13".)

Superstition says it’s the unluckiest day of the year and is generally regarded as an unsuitable day to undertake journeys or begin new projects.

Among the tragedies to befall this day were the bombing of Buckingham Palace on September 13, 1940, as part of Hitler's strategic "Blitz" bombing campaign.

November 13 1970 (also a Friday) saw a massive storm kill around 300,000 people in Bangladesh, with subsequent floods killing as many as a million in the Ganges Delta.

What's more, some people say Jesus Christ was crucified on Friday the 13th.

Some websites list the birth of the Olsen twins on this date as similarly sinister....

Have you ever had an unlucky event befall you on this date? Tell us about it in comments below.

Take a look below at 13 examples of reactions to the belief that 13 is an unlucky number:

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  • It's in the cards

    Tarot Card number 13 is the Death Card, depicting the Grim Reaper.

  • No room in the inn

    Hospitals and hotels regularly have no room number 13.

  • On the street

    Many cities don't have a 13th Street or a 13th Avenue. This city tempted fate.

  • Blame your parents

    If you have 13 letters in your name, you're said to have the devil's luck. Like, this guy (Charles Manson).

  • Checking in

    Many airports skip the 13th gate.

  • Aisle omission

    Airplanes have no 13th aisle.

  • Numero...?

    Italians omit the number 13 from their national lottery.

  • Unlucky height

    More than 80% of high rises lack a 13th floor

  • One solution

    On streets in Florence, Italy, the house between number 12 and 14 is addressed as 12 and a half.

  • Hangman's noose

    Traditionally in hangings, there are 13 knots in the noose and 13 steps leading up to the moment of death.

  • Dinner luck

    French President Nicolas Sarkozy may know that in France, socialites called quatorziens (fourteeners) make themselves available as 14th guests to keep a dinner party from an unlucky fate.

  • Space travel

    Many say the No. 13 pointed to the ill-fated mission to the moon, Apollo 13.

  • Ancient ties

    Some say that the Babylonian Code of Hammurabi (circa 1780 B.C.E.) is to blame for the No. 13 woes since the 13th law is omitted.