How the Date of Mardi Gras Is Determined

Mardi Gras (Fat Tuesday) is not a fixed monthly date. It is a movable Christian feast tied to the Easter cycle.

The Rule

Mardi Gras = the day before Ash Wednesday.

Easter Connection

• Easter Sunday = first Sunday after the first full moon on/after 21 March (vernal equinox).
• Lent = 40 days (excluding Sundays) before Easter.
• Ash Wednesday = 46 days before Easter Sunday.
• Therefore, Mardi Gras = 47 days before Easter Sunday.

Result

Mardi Gras falls between 3 February and 9 March inclusive. It shifts annually; e.g., 2024: 13 Feb, 2025: 4 Mar, 2026: 17 Feb.

Local Calendars

New Orleans, Mobile, Rio, Venice, and other Carnival cities publish multi‑year schedules based on this computation.