Pancake Tuesday was a religious festivity.
The Fifth Doctor boasted that his TARDIS beat an escape pod any day of the week, "except perhaps Pancake Tuesdays." (AUDIO: Empire of the Racnoss)
The Eleventh Doctor compared the Festival of Offerings to it when explaining it to Clara Oswald. (TV: The Rings of Akhaten)
Behind the scenes[]
In the real world, Pancake Tuesday is celebrated on the same day as Mardi Gras.