Mardi Gras, or “Fat Tuesday,” is the final day of Carnival before Lent. Parades including Rex, Zulu, and Argus roll on that day. The day of parades culminate in truck float parades. Carnival officially ends when Rex meets Comus at the Meeting of the Courts.

The day of Mardi Gras is floating because it is decided by figuring out the Day of Easter. Easter follows the first full moon that happens on or after the spring equinox (March 21). Mardi Gras, thus is figured out by counting backward 47 days before Easter Sunday. Because of the Easter range, Mardi Gras can happen as early as February 3 or as late as March 9.