SOME people will refuse to leave their homes; a few will not even venture out of bed. They are among the millions of people who believe Friday the 13th is unlucky. As many as one in four are believed to subscribe to the superstition, according to research.
If you are one of them, 2012 may not be your year. There will be three Friday the 13ths: this coming Friday, then two more in April and July.
The Independent has investigated the superstitions, events and strange happenings associated with the date. There are 13 of them, so look away now if you are triskaidekaphobic (afraid of the number 13).
1. The fear of Friday the 13th is known by one of two names: paraskevidekatriaphobia (stemming from the Greek words for Friday, 13 and fear), or friggatriskaidekaphobia (Friday derives its name from the Norse goddess Frigga and triskaidekaphobia is the fear of the number 13).
2. Friday 13 August, 2010 proved particularly unlucky for a 13-year-old boy who was struck by lightning at Lowestoft Seafront Air Festival in Suffolk. To add to the strangeness, the time when St John Ambulance volunteers treated him was 13.13. Luckily, he suffered only a minor burn.
3. When an aircraft crashed in the Andes on Friday 13 October, 1972, survivors had to resort to cannibalism, eating the dead passengers to survive before being rescued more than two months later.
4. The heavy metal band Black Sabbath released their eponymous debut album on Friday 13 February, 1970.
5. An article, Is Friday 13th bad for your health?, published in the British Medical Journal in 1993 concluded the date was unlucky for some and that it might be safer to stay at home. The authors found "the risk of hospital admission as a result of a transport accident may be increased by as much as 52 per cent".
6. Research in 2003 suggested people who thought they were unlucky were more likely to believe in superstitions linked to bad luck which could, in turn, actually lead to bad luck. Psychologist Professor Richard Wiseman, of the University of Hertfordshire, said Friday the 13th could make some people anxious and therefore more accident-prone.
7. Nevertheless, every Friday 13th, motorbike enthusiasts gather in Port Dover in Ontario, Canada, to celebrate. The tradition, said to have started in 1981 with about 25 friends, is now enjoyed by thousands of bikers and visitors.
8. A virus programmed to delete files struck IBM computers across Britain on Friday 13 January 1989.
9. Tube trains were cleared out of the path of a runaway engineering train, which went through six stations during a 13-minute journey on London's Underground, on Friday 13 August last year. The unmanned train, which had become uncoupled when being towed, ran for nearly four miles on the Northern Line.
10. American rapper Tupac Shakur died on Friday 13 September 1996 after being shot six days earlier.
11. Friday 13 May, 1927 became known as Black Friday after the stock market in Berlin collapsed.
12. There are many proposed origins of the Friday the 13th superstition, including some linked to the Bible. One theory is based on an amalgamation of two ideas: 13 is unlucky because there were 13 diners at the Last Supper and Friday is unlucky because it is the day when Jesus was crucified.
13. More than 60 million people worldwide are reported to suffer from fear of Friday the 13th. Dr Donald Dossey, of the Stress Management Center/Phobia Institute in Asheville, North Carolina, estimates this costs as much as $900m to the US alone.