Eton's best-known holiday takes place on the so-called "Fourth of June", a celebration of the birthday of King George III, Eton's greatest patron. This day is celebrated with the Procession of Boats, in which the top rowing crews from the top four years row past in vintage wooden rowing boats. Similar to the Queen's Official Birthday, the "Fourth of June" is no longer celebrated on 4 June, but on the Wednesday before the first weekend of June. Eton also observes St. Andrew's Day, on which the Eton wall game is played.[citation needed]

What is Eton's best-known holiday?