What does the 13 Friday means?

Answer 1

There have been a number of events known as "Black Fridays" in history. Usually, these events are devastating.

Some historians propose that the origin of the "Black Friday" was the simultaneous arrest of hundreds of Knights Templars on October 13, 1307 (Friday), to be later tortured into "admitting" heresy.

Today, the concept of Friday the 13th has been extended through the 'black Friday' concept to incorporate anything really bad that happens on a Friday. In history there have been a number of events that happened on a Friday and are known as Black Friday:

Black Friday (1869), a financial crisis in the United States
Black Friday (1889), the day of the Johnstown Flood.
Black Friday (1910), WSPU took militant action when the Conciliation Bill failed.
Black Friday (1919), a riot in Glasgow stemming from industrial unrest
Black Friday (1921), day on which British dockers' and railwaymen's union leaders announced their decision not to call for strike action against wage reductions for miners
Black Friday (1929), a stock market crash in the United States
Black Friday (1939), a day of devastating fires in Australia
Black Friday (1945), largest air battle over Norway, over Sunnfjord
Hollywood Black Friday (1945), the day the six-month-old Confederation of Studio Unions (CSU) strike boiled over into a bloody riot at the Warner Bros. studios leading to the eventual breakup of the CSU.
Black Friday (1978), a massacre of protesters in Iran
Black Friday (1982), known in Britain after Argentina invaded the Falkland Islands, sparking the Falklands War
Black Friday (1987), the day an hour-long F4 category tornado ran through the city of Edmonton, Alberta, Canada
Black Friday (2004), a crackdown on a peaceful protest in the capital city of Maldives, Malé

Other uses of the term include:

Black Friday, a name used for any Friday which falls on the 13th of a month
Black Friday, the Friday preceding Easter, also known as Good Friday or God Friday.
Black Friday (shopping), the day after Thanksgiving Day in the United States, the first shopping day of the Christmas season and one of the busiest shopping days of the year
"Black Friday" is the name given to the last Friday before Christmas in the United Kingdom. It is a day when widespread anti-social behaviour due to public alcohol consumption is expected to occur, and police are given additional powers to combat it
Black Friday (1940 film), a science-fiction/horror film starring Boris Karloff, Stanley Ridges and Bela Lugosi
Black Friday (2005 film), a Hindi film on the 1993 serial bomb blasts in Mumbai, directed by Anurag Kashyap
"Black Friday", a title of a song by Grinspoon
"Black Friday", a title of a song by Steely Dan
"Black Friday", a title of a song by Megadeth
"Black Friday Rule", a title of a song by Flogging Molly
"Black Friday", the nickname for game 3 of the 1977 NLCS baseball championships. Philadelphia Phillies fans gave the nickname because the Phillies blew an early lead against the Los Angeles Dodgers and a controversial call was made during the game
"Black Friday", a title of a poem written by Dennis Rader, the BTK killer

PS: Jesus Christ died on Friday.
The Chinese think the number 13 is bad luck since:
1+3= 4
Four in Chinese also means death
Judas [the one who betrayed Jesus] is the 13th apostle.

Answer 2

A Friday occurring on the 13th day of any month is considered to be a day of bad luck in English, German, Polish and Portuguese-speaking cultures around the globe. Similar superstitions exist in some other traditions. In Greece or Spain, for example, Tuesday the 13th takes the same role. The fear of Friday the 13th is called paraskavedekatriaphobia.

Answer 3

It was Friday the 13th 1307 that the Pope ordered the execution of the Knights Templar.

Before then there were no evils associated with the date.

Answer 4

The day the Marines invaded to conquer Iwo Jima. Other than that, it has no meaning.