In new Orleans it is Mardi Gras or Fat Tuesday. In other cities in the world it is Carnival. Venice, Rio De Janeiro, Sao Paulo are some of the biggest Carnival celebrations. This Festival has it's roots in the Pagan festival Saturnalia which was adapted to chritianity. Carnival/Mardi Gras is the last day of indulging before the christian fast that follows (Ash Wednesday until Easter). This Year 2012 will land on Tuesday February 21st. The word Carnival comes from Carnelevre/Carnevare which in essence means to give up eating meat. Mardi Gras/Fat Tuesday meaning a last day to gourge before the fast.