Friday the 13th
Friday the 13th, also known as Black Friday in some countries, is considered an unlucky day in Western superstition. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday. There is no written evidence for a "Friday the 13th" superstition before the 19th century, and the superstition only gained widespread distribution in the 20th century. The fear of the number 13 has been given a scientific name: triskadekaphobia; and on analogy to this the fear of Friday the 13th is called paraskevidekatriaphobia, from the Greek words Paraskeví (Παρασκευή, meaning "Friday"), and dekatreís (δεκατρείς, meaning "thirteen"). 
It's not known for certain how the superstition surrounding this day arose, but the probable story is that both Friday and the number 13 were traditionally considered unlucky because of their connection with the crucifixion of Christ (Friday being the day the crucifixion took place and was commemorated weekly in Catholic practice, and 13 being the number of people present at the' last supper). According to Phillips Stevens, Jr., associate professor of anthropology at the University at Buffalo (SUNY), "There were 13 people at the table (at the Last Supper) and the 13th was Jesus. The Last Supper was on a Thursday, and the next day was Friday, the day of crucifixion. When '13' and Friday come together, it is a double whammy."
However, folklorists maintain that there is no written evidence for a "Friday the 13th" superstition before the 19th century. An early documented reference in English occurs in Henry Sutherland Edwards' 1869 biography of Gioachino Rossini, who died on a Friday 13th:
He [Rossini] was surrounded to the last by admiring friends; and if it be true that, like so many Italians, he regarded Fridays as an unlucky day and thirteen as an unlucky number, it is remarkable that on Friday 13th of November he passed away.
It's possible that the publication in 1907 of Thomas W. Lawson's popular novel Friday, the Thirteenth, contributed to disseminating the superstition. In the novel, an unscrupulous broker takes advantage of the superstition to create a Wall Street panic on a Friday the 13th.
Other possible contributing factors include:
- In numerology, the number twelve is considered the number of completeness, as reflected in the twelve months of the year, twelve hours of the clock day, the twelve deities of Olympus, twelve tribes of Israel, twelve Apostles of Jesus, the 12 successors of Muhammad in Shia Islam, twelve signs of the Zodiac, the 12 years of the Chinese Buddhist cycle, etc. In contrast the number thirteen is considered irregular, transgressing this completeness.
- There is a superstition, thought by some to derive from the Last Supper or a Norse myth, that having thirteen people seated at a table results in the death of one of the diners.
- On Friday, 13 October 1307, hundreds of the Knights Templar were arrested in France, possibly giving rise to the fear of a curse on that day. This connection between the Friday the 13th superstition and the Knights Templar was popularized in Dan Brown's 2003 novel The Da Vinci Code and in John J. Robinson's 1989 work Born in Blood: The Lost Secrets of Freemasonry, and also in the Maurice Druon historical novel series: "The Accursed Kings" (French: Les Rois Maudits). However, experts agree that this is a relatively recent correlation, and most likely a modern-day invention.
Tuesday the 13th (Hispanic & Greek culture)
In Spanish-speaking countries, instead of Friday, Tuesday the 13th (martes trece) is considered a day of bad luck. The Greeks also consider Tuesday (and especially the 13th) an unlucky day. Tuesday is considered dominated by the influence of Ares, the god of war. A connection can be seen in the etymology of the name in some European languages (Mardi in French or martes in Spanish). The fall of Constantinople to the Fourth Crusade occurred on Tuesday, April 13, 1204, and the Fall of Constantinople to the Ottomans happened on Tuesday, 29 May 1453, events that strengthen the superstition about Tuesday. In addition, in Greek the name of the day is Triti (Τρίτη) meaning literally the third (day of the week), adding weight to the superstition, since bad luck is said to "come in threes".[dubious ]
Friday the 17th (Italy)
In Italian popular culture, Friday the 17th (and not the 13th) is considered a day of bad luck. The origin of this belief could be traced in the writing of number 17, in ancient Latin: XVII. By shuffling the digits of the number you can easily get the word VIXI (I lived, hence now I'm dead) omen of bad luck. In fact, in Italy, 13 is generally considered a lucky number. However, due to Americanization, young people consider Friday the 13th unlucky as well.
The 2000 parody film Shriek If You Know What I Did Last Friday the Thirteenth was released in Italy with the title Shriek – Hai impegni per venerdì 17? ("Shriek – Do You Have Something to Do on Friday the 17th?").
According to the Stress Management Center and Phobia Institute in Asheville, North Carolina, an estimated 17 to 21 million people in the United States are affected by a fear of this day, making it the most feared day and date in history. Some people are so paralyzed by fear that they avoid their normal routines in doing business, taking flights or even getting out of bed. "It's been estimated that [US]$800 or $900 million is lost in business on this day". Despite this, representatives for both Delta Air Lines and Continental Airlines have stated that their airlines do not suffer from any noticeable drop in travel on those Fridays.
In Finland, a consortium of governmental and nongovernmental organizations led by the Ministry of Social Affairs and Health promotes the National Accident Day, which always falls on a Friday 13th.
Rate of accidents
A study in the British Medical Journal, published in 1993, concluded that there "is a significant level of traffic-related incidences on Friday the 13th as opposed to a random day, such as Friday the 6th, in the UK." However, the Dutch Centre for Insurance Statistics (CVS) on 12 June 2008 stated that "fewer accidents and reports of fire and theft occur when the 13th of the month falls on a Friday than on other Fridays, because people are preventatively more careful or just stay home. Statistically speaking, driving is slightly safer on Friday the 13th, at least in the Netherlands; in the last two years, Dutch insurers received reports of an average 7,800 traffic accidents each Friday; but the average figure when the 13th fell on a Friday was just 7,500."
On Friday 13 October 1972 a plane carrying 45 Uruguayan passengers and crew including members of the Old Christian rugby team and their family members and associates crashed in the Andes mountains after veering off route to Santiago, Chile. 16 of the 45 on board ultimately survived after spending 72 days in unimaginable conditions. It is heralded as one of the greatest human survival stories of all time.
The following months have a Friday the 13th:
|January||1978, 1984, 1989, 1995, 2006, 2012, 2017, 2023, 2034||A, AG|
|February||1976, 1981, 1987, 1998, 2004, 2009, 2015, 2026, 2032, 2037||D, DC|
|March||1981, 1987, 1992, 1998, 2009, 2015, 2020, 2026, 2037||D, ED|
|April||1973, 1979, 1984, 1990, 2001, 2007, 2012, 2018, 2029, 2035||G, AG|
|May||1977, 1983, 1988, 1994, 2005, 2011, 2016, 2022, 2033||B, CB|
|June||1975, 1980, 1986, 1997, 2003, 2008, 2014, 2025, 2031, 2036||E, FE|
|July||1973, 1979, 1984, 1990, 2001, 2007, 2012, 2018, 2029, 2035||G, AG|
|August||1976, 1982, 1993, 1999, 2004, 2010, 2021, 2027, 2032||C, DC|
|September||1974, 1985, 1991, 1996, 2002, 2013, 2019, 2024, 2030||F, GF|
|October||1972, 1978, 1989, 1995, 2000, 2006, 2017, 2023, 2028, 2034||A, BA|
|November||1981, 1987, 1992, 1998, 2009, 2015, 2020, 2026, 2037||D, ED|
|December||1974, 1985, 1991, 1996, 2002, 2013, 2019, 2024, 2030||F, GF|
This sequence given here for 2001–2028, follows a 28-year cycle from 1 March 1900 to 28 February 2100. The months with a Friday the 13th are determined by the Dominical letter (G, F, GF, etc.) of the year. Any month that starts on a Sunday contains a Friday the 13th, and there is at least one Friday the 13th in every calendar year. There can be as many as three Friday the 13ths in a single calendar year; either in February, March and November in a common year starting on Thursday (such as 2009 or 2015) (D), or January, April and July in a leap year starting on Sunday (such as 2012) (AG).
The longest period that can occur without a Friday the 13th is fourteen months, either from July to September the following year being a common year starting on Tuesday (e.g., between 2001–02, 2012–13, and 2018–19), or from August to October the following year being a leap year starting on Saturday (e.g., between 1999–2000 or 2027–28).
Patterns for common years:
Each Gregorian 400-year cycle contains 146,097 days (365 × 400 = 146,000 normal days, plus 97 leap days). 146,097 days ÷ 7 days per week = 20,871 weeks. Thus, each cycle contains the same pattern of days of the week (and thus the same pattern of Fridays that are on the 13th). The 13th day of the month is slightly more likely to be a Friday than any other day of the week. On average, there is a Friday the 13th once every 212.35 days (compared to Thursday the 13th, which occurs only once every 213.59 days).
The distribution of the 13th day over the 4,800 months is as follows:
|Day of the week||Sunday||Monday||Tuesday||Wednesday||Thursday||Friday||Saturday|
|Number of occurrences||687||685||685||687||684||688||684|
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- name=mathworld>Weisstein, Eric W. "Triskaidekaphobia on MathWorld". MathWorld. Retrieved 14 August 2010.
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- Weisstein, Eric W. "Triskaidekaphobia on MathWorld". MathWorld. Retrieved 14 August 2010.
- Nathaniel Lachenmeyer, 13: The Story of the World's Most Popular Superstition ch. 5 (2004).
- Roach, John (12 August 2004). "Friday the 13th Phobia Rooted in Ancient History". National Geographic News. Retrieved 29 October 2008.
- Clar, Mimi (1957). "Friday the 13th". Western Folklore: 62–63.
- Henry Sutherland Edwards, The Life of Rossini, Blackett, 1869, p.340.
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- Rafael Falcón, Christine Yoder Falcón Salsa: a taste of Hispanic culture, p. 64, Praeger (1998), ISBN 0-275-96121-4
- Carlo Grande (17 February 2012). "Venerdì 17 porta davvero sfortuna?" (in Italian). La Stampa. Retrieved 31 March 2012.
- "Venerdì 13 porta (s)fortuna? Non in Italia" (in Italian). cafebabel.com. Retrieved 31 March 2012.
- "Venerdì 13 è un giorno che porta sfortuna – Mara rimanda le nozze con Mezzaroma" (in Italian). Corriere del Mezzogiorno. 1 February 2011. Retrieved 31 March 2012.
- Josh Sens, "Some Don't Count on lucky", Via Magazine, January 2004.
- http://www.tyosuojelu.fi/fi/ajankohtaista/5757 http://www.tapaturmapäivä.fi/fi/
- Roach, John. "Friday the 13th Phobia Rooted in Ancient History". National Geographic Society. Retrieved 15 June 2014.
According to a 1993 study in the British Medical Journal, however, there is a significant level of traffic-related incidences on Friday the 13th as opposed to a random day, such as Friday the 6th, in the UK.
- Mirror.co.uk, "Friday 13th is no longer unlucky".
- Dutch study shows Friday 13th not more unlucky, Reuters.com
- "Historia del accidente - Día a día". viven.com. Retrieved 1 December 2014.
- Bodin, Magnus (13 November 1998). "About the date+day-distribution along the epoch". x42. Retrieved 13 November 1998.
- B.H. Brown and Raphael Robinson, "Solution to Problem E36", American Mathematical Monthly, vol. 40, issue 10 (1933), p. 607; Jean Meeus, Mathematical Astronomy Morsels IV, 2007, p. 367.
|Look up paraskavedekatriaphobia in Wiktionary, the free dictionary.|
- Some don't count on Lucky 13 – Via Magazine
- Calendar Showing Friday 13s, Robslink.com
- S&P 500 Performance on Friday 13s, dailyspeculations.com
- All Ords Performance on Friday 13s, asxiq.com