Happy Mardi Gras! The Mardi Gras tradition, also known as Carnival, is a huge celebration before the 40 days of Lent in the Christian calendar; Lent is the liturgical season before Easter, and is marked by fasting, the giving of alms, and other forms of penance and self-denial. Mardi Gras (which means, "Fat Tuesday") is the last day for celebration before Lent begins. So, laissez les bons temps rouler (let the good times roll)!
Read more about the medieval roots of Mardi Gras here: http://www.medievalists.net/2015/02/reverent-irreverence-mardi-gras/