In England, and countries where the Anglican church has predominated, the Tuesday before Lent is known as 'Shrove Tuesday' from the word 'shrive' (to confess), which is what people traditionally did prior to Ash Wednesday. It is also known as 'Pancake day' when we traditionally indulge ourselves on things which were once forbidden during Lent.
Across Europe the day has various names mostly all tending to mean 'Fat Tuesday', such as 'Mardi Gras'. In the Catholic and originally French parts of the United States it is called 'Mardi Gras'.
But what is Fat Tuesday called across the vast swathe of protestant USA?
By the way it is next Tuesday, 3rd March - one of its latest possible dates - since Easter is so late this year.