This document discusses April 23rd and notable events that occurred on this date, including: 1) It is the birthday of William Shakespeare and Saint George's Day. Shakespeare died on his birthday in 1616 at the age of 52. 2) Miguel de Cervantes, the author of Don Quixote, also died on April 23rd, 1616, but 10 days before Shakespeare. This is because Spain adopted the Gregorian calendar in 1582, which removed 10 days from the calendar. 3) UNESCO designated April 23rd as World Book Day, inspired by its celebration in Catalonia, though World Book Day in the UK is celebrated in March.