![image: [ Friday the 13th is the one to watch if you are accident prone ]](/olmedia/60000/images/_64949_fri13_300.jpg)
The myth is so strong it has even spawned its own Hollywood horror movie series featuring Jason Voorhees, a psychopath in an ice hockey mask who is driven to acts of mindless violence by the very mention of that day.
Studies show millions of pounds and dollars are lost as the superstitious among us cancel travel plans, put off purchases or even stay off work altogether.
Numerous disasters have occurred on Friday the 13th, most notorious of which was the plane crash in the Andes in 1972 which turned the survivors into cannibals.
Winston Churchill was known to postpone car or plane journeys if it meant avoiding those dreaded 24 hours and diners at the Savoy Hotel in London are encouraged to pull up a spare chair for Kaspar, a carved black cat, if their parties number 13.
The cat statue has been used since 1898, when South African businessman Wolf Joel was murdered shortly after hosting a dinner party for 13 on Friday the 13th.
Superstitious sailors
Seafarers tend to take superstitions very seriously and you will find few British skippers willing to set sail on a ship's maiden voyage on a Friday.
This dates back to the 18th century when HMS Friday sailed into oblivion ... on a Friday.
But how can a date which occurs naturally at least once every seven months really bring bad luck and why are we not trembling in our boots at the thought of an impending Wednesday the 25th ?
Trembling in the Middle Ages
Professor Ronald Hutton, of Bristol University, says: "The origins of Friday the 13th as a superstition date back to the Middle Ages but were strengthened in the 16th and 17th centuries. Half of it is purely Christian."
Prof Hutton says: "Friday is regarded as an unlucky day because it was believed to be the day Jesus was crucified. There were also 13 around the table at The Last Supper.
"Ironically Friday was considered a lucky day by the Romans, who associated it with Venus, goddess of love. Hence the French name for it: Vendredi."
He says 12 was traditionally considered a lucky number -- there were 12 tribes of Israel and 12 moons in the year for example -- and 13 was therefore unlucky.
Prof Hutton says it is possible the authors of the Bible deliberately ignored some of Jesus's followers to leave him with 12 apostles because it was considered a "magic" number.
But the bad luck may have started with Loki, the Norse god of mischief, who gatecrashed a party of 12. Baldur, god of light, died during the banquet in Valhalla.
Suffering from Triskaidekaphobia?
Friday the 13th was a potent symbolic date in the Middle Ages and the superstition remains widespread in Britain, Ireland, the United States, Australasia and parts of continental Europe.
Prof Hutton says the superstition is rapidly weakening and few people nowadays give it much thought but he added: "Having said that whenever I have flown the Atlantic on a Friday the 13th I notice the plane is much emptier."
He says: "Human beings have always tried to come to terms with fate and try to be predictive.
"Of course the law of averages says there is nothing in it and there is no reason why one day should be luckier than another."
But if you suffer from triskaidekaphobia -- fear of the number 13 -- 1998 is a bad year. There were Friday the 13ths in February and March and another one is due in November.
What's in a number ?
(12 Mar 98 | World)
Superstitions
Scary Superstitions
Friday the 13th (horror movie fan site)
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