Shrove Tuesday is the last day of indulgence before Christians traditionally move into a 40-day period of abstinence that marks the lead up to Easter.
It takes its name from the word "shrive", meaning to confess and seek absolution.
In many parts of the world, it is also known as Pancake Tuesday, a tradition borne out of households cooking pancakes the day before Lent begins.
Fats, eggs and milky foods once counted among the items observant Christians wouldn't eat during Lent. Pancakes were a dish that could use up all these items - just add flour.
This religious observance also gave rise to the French term "Mardi Gras", which means "Fat Tuesday".
As American Catholic notes, this is why New Orleans' famous party abruptly ends when the clock strikes midnight, and Ash Wednesday begins.
This year's Shrove Tuesday falls on February 9, ahead of Easter on March 27.
