Where did the idea behind Friday the 13th being a bad day come from and why?

Answer 1

The reasons why Friday came to be regarded as a day of bad luck have been obscured by the mists of time — some of the more common theories link it to a significant event in Christian tradition said to have taken place on Friday, such as the Crucifixion, Eve's offering the apple to Adam in the Garden of Eden, the beginning of the Great Flood, or the confusion at the Tower of Babel. Chaucer alluded to Friday as a day on which bad things seemed to happen in the Canterbury Tales as far back as the late 14th century ("And on a Friday fell all this mischance"), but references to Friday as a day connected with ill luck generally start to show up in Western literature around the mid-17th century:
From the early 19th century onward, examples abound of Friday's being considered a bad day for all sorts of ordinary tasks, from writing letters to conducting business and receiving medical treatment:
Friday was also said to be a particularly unlucky day on which to undertake anything that represented a beginning or the start of a new venture, thus we find references to all of the following activities as endeavors best avoided on Fridays: needleworking, harvesting, laying the keel of, or launching, a ship, beginning a sea voyage, beginning a journey, giving birth, getting married, recovering from illness, hearing news, moving and starting a new job.
In some cases, Good Friday (the Friday before Easter) was regarded as an exception or 'antidote' to the bad luck usually associated with Friday beginnings.
The origins of the connection between the number thirteen and ill fortune are similarly obscure. Many different sources for the superstition surrounding the number thirteen have been posited, the most common stemming from another Christian source, the Last Supper, at which Judas Iscariot was said to have been the thirteenth guest to sit at the table. (Judas later betrayed Jesus, leading to His crucifixion, and then took his own life.) This Christian symbolism is reflected in early Western references to thirteen as an omen of bad fortune, which generally started to appear in the early 18th century and warned that thirteen people sitting down to a meal together presaged that one of them would die within the year:
Superstition held that the victim would be the first person to rise from the table (or the last one to be seated), leading to the remedies of having all guests sit and stand at the same time, or seating one or more guests at a separate table.
More generally, groups of thirteen people in any context — at a table, in a room, on a ship — were believed to inevitably lead to tragedy.
By the late 19th century the superstition surrounding thirteen had become even more general, with people going out of their ways to avoid anything designated by the number thirteen, whether it be hotel rooms, desks, or cars:
Once again these ill omens were avoided through artifice, such as the renumbering of rooms in hotels and inns to eliminate any Room #13's, and misnumbering the floors above the 12th floor in multi-story buildings so that tenants could pretend 13th floors were really 14th floors.
Just as Friday was considered an inauspicious day of the week on which to embark upon a new enterprise, so the 13th day of a month came to signify a particularly bad day for beginning a venture. Although regarding the confluence of a particularly unlucky day of the week (Friday) and a particularly unlucky day of the month (the 13th) as a date of supreme unluckiness might seem to be obvious and inevitable, superstitions regarding Friday the 13th are not nearly as old as most people tend to think. The belief in Friday the 13th as a day on which Murphy's Law reigns supreme and anything that can go wrong will go wrong appears to be largely a 20th century phenomenon. (The claim that the Friday the 13th superstition began with the arrest of the final Grand Master of the Knights Templar, Jacques Demolay, on Friday, October 13, 1307, is a modern-day invention.)
Books of English folklore generally cite a 1913 Notes & Queries reference as the earliest known expression of Friday the 13th as a day of evil luck, and this corresponds to what we found when we searched The New York Times and the Los Angeles Times for similar references. In both newspapers the first mentions of the ill-fated date occured in 1908.

Answer 2

the most recent thing i read about it was it was the date that the pope at the time decreed that all the Knights of the Templar were heretics and should be put to death. Apparently it was all co-ordinated so that it all happened on Friday the 13th (cant remember the month - but it was in the 12th or 13th century

Answer 3

http://people.howstuffworks.com/friday-thirteenth.htm

Answer 4

It's superstition. Not entertainment.

Answer 5

This one is pretty good:
http://en.wikipedia.org/wiki/Friday_the_13th

This one covers several different cultural explanations:
http://www.crystalinks.com/friday13th.html

I liked this one best:
http://www.wilsonsalmanac.com/friday13.html

Answer 6

ii'd like to know too.. i mean really waht's the big deal, eh??