The story behind Friday the 13th?

According to some experts, the belief that Friday the 13th is a particularly unlucky day is a modern amalgamation of two older superstitions: that thirteen is an unlucky number and that Friday is an unlucky day. It is not an ancient superstition, and it does not refer to any particular historical Friday the 13th. In numerology, the number twelve is considered the number of completeness, as reflected in the twelve months of the year, twelve signs of the zodiac, twelve hours of the clock, twelve tribes of Israel, twelve Apostles of Jesus, twelve gods of Olympus, etc. Whereas the number thirteen was considered irregular, transgressing this completeness. There is also a superstition, thought by some to derive from the Last Supper or a Norse myth, that having thirteen people seated at a table will result in the death of one of the diners. Friday has been considered an unlucky day at least since the 14th century's The Canterbury Tales, and many other professions have regarded Friday as an unlucky day to undertake journeys or begin new projects. Black Friday has been associated with stock market crashes and other disasters since the 1800s. Despite the reputation of the two separated elements, there is no evidence for a "Friday the 13th" superstition before the 19th century, and folklore historians state that Friday the 13th was a convergence of the superstitions about "Friday" and "13". The earliest known reference in English occurs in an 1869 biography of Gioachino Rossini: [Rossini] was surrounded to the last by admiring and affectionate friends; and if it be true that, like so many other Italians, he regarded Friday as an unlucky day, and thirteen as an unlucky number, it is remarkable that on Friday, the 13th of November, he died. Though the superstition developed relatively recently, much older origins are often claimed for it, most notably in the 2003 novel The Da Vinci Code, which declares that the superstition began with the arrest of the Knights Templar on Friday 13 October 1307. This is a modern-day invention. As discussed in one serious account: No one has been able to document the existence of such beliefs prior to the 19th century. If people who lived before the late 1800s perceived Friday the 13th as a day of special misfortune, no evidence has been found to prove it. As a result, some scholars are now convinced the stigma is a thoroughly modern phenomenon exacerbated by 20th-century media hype. Going back a hundred years, Friday the 13th doesn't even merit a mention in E. Cobham Brewer's voluminous 1898 edition of the Dictionary of Phrase and Fable, though one does find entries for "Friday, an Unlucky Day" and "Thirteen Unlucky." When the date of ill fate finally does make an appearance in later editions of the text, it is without extravagant claims as to the superstition's historicity or longevity.