Shrove Tuesday (also known as Mardi Gras, Pancake Tuesday or Pancake Day) is the final day of Shrovetide, marking the end of pre-Lent. Lent begins the following day with Ash Wednesday. Shrove Tuesday is observed in many Christian countries through participating in confession and absolution, the ritual burning of the previous year's Holy Week palms, finalizing one's Lenten sacrifice, as well as eating pancakes and other sweets.

https://en.wikipedia.org/wiki/Shrove_Tuesday