Pancake Day

Tuesday before Ash Wednesday is Shrove Tuesday. It is also called Pancake Day.

Pieter Bruegel the Elder: The Fight between Carnival and Lent, 1559, oil on panel - Wikipedia

shrove - to shrive (veraltet) beichten

Shrove Tuesday die Fastnacht, Fastnachtsdienstag
Shrovetide der Fasching, die Fastnacht; die Fastnachtszeit, die drei letzten Tage vor der Fastenzeit 
Shrove Monday ist wenig gebräuchlich für Rosenmontag. Es wird verwendet in: 
Shrove Monday procession der Rosenmontagszug 
Da man im UK keinen Rosenmontagszug hat, beschreibt es gewöhnlich die Rosenmontagszüge auf dem Kontinent.
Lent die Fastenzeit

Shrove Tuesday was once known as a "half-holiday" in England. It started at 11:00am with the ringing of a church bell. On Pancake Day, "pancake races" are held in villages and towns across the United Kingdom. The tradition is said to have originated when a housewife from Olney was so busy making pancakes that she forgot the time until she heard the church bells ringing for the service. She raced out of the house to church while still carrying her frying pan and pancake. The pancake race remains a relatively common festive tradition in the UK, especially England, even today. Participants with frying pans race through the streets tossing pancakes into the air and catching them in the pan whilst running. (Source: wikipedia)

Pancake Race in Olney  (where it all began)