Always a party town, especially the French Quarter, New Orleans hosts "America's biggest party". Mardi Gras, with French origins, falls on "Fat Tuesday", the day before Ash Wednesday, 47 days before Easter (the 40 days and 7 Sundays of Lent). It can be any Tuesday from February 3 through March 9, because of the fluctuating date for Easter, as set by the Gregorian calendar and established by the Catholic Church (Easter's exact date was set to coincide with the first Sunday after the full moon that follows the Spring Equinox.)
The New Orleans 2011 Mardi Gras season begins February 25 and runs through March 8, Fat Tuesday/Mardi Gras Day.
"Carnival" season starts the 12th Night Feast of Epiphany (the day the three kings visited the Christ Child). Mardi Gras, French for Fat Tuesday, is the single-day climax of the season.
The location of the city, size, and French influence in the French Quarter, has made New Orleans the home of the biggest and most famous of Mardi Gras celebrations. During the 12 days leading up to New Orleans Mardi Gras, nearly 70 parades are held. Trinkets have been tossed off floats since 1871. "Krewes" are clubs that celebrate and sponsor Mardi Gras events and parades. The biggest parades are on the last three days combining over a 100 floats and nearly 100 marching bands. The krewes' members toss more than 2 million plastic drink cups, 3 1/2 million doubloons and 350,000 gross of beads to crowds chanting "throw me something mister" (and some who flash their breasts). Fat Tuesday is a legal holiday in New Orleans - when half the town comes out in costume to watch the other half parade. Then, at midnight, the party's over, as Ash Wednesday starts the Lenten season.