Wikipedia
Shrove Monday
Shrove Monday, sometimes known as Collop Monday, Rose Monday, Merry Monday or Hall Monday, is the Monday before Ash Wednesday every year. A part of the English traditional Shrovetide celebrations of the week before Lent, the Monday precedes Shrove Tuesday. As the Monday before Ash Wednesday, it is part of diverse Carnival celebrations which take place in many parts of the Christian world, from Greece, to Germany, to the Mardi Gras and Carnival of the Americas.
Usage examples of "shrove monday".
Yes, it was on Shrove Monday that I decided to join in the festivities, to put on a costume and to add a costumed Oskar to the motley throng.