In which of Geoffrey Chaucer's The Canterbury Tales is there a disputed reference to April Fool's Day?
Answer: "The Nun's Priest's Tale"
More information: In the "Nun Priest's Tale", there is a reference to "32 March", which of course doesn't exist and by inference would be 1 April. However, there is a debate as to whether it was actually written so, or if that phrase is a mistranslation.