Fat Tuesday is a day of revelry that includes parades, parties, and gastronomic indulgence before the Christian fasting season of Lent begins on Ash Wednesday. It is also called Shrove Tuesday, Carnival Tuesday, or Pancake Tuesday, depending on where the celebration is taking place. Fat Tuesday is celebrated exactly 47 days before Easter Sunday, and the date can vary from as early as February 3 to as late as March 9.
Fat Thursday is a Christian tradition in some countries marking the last Thursday before Lent and is associated with the celebration of Carnival. Because Lent is a time of fasting, the days leading up to Ash Wednesday provide the last opportunity for feasting (including simply eating forbidden items) until Easter.
In summary, Fat Tuesday is not a day of the week, but rather a specific day of celebration that occurs before the start of Lent.
