At the end of any stage except Bosses, touch the flag when the last two digits of the clock are the same (for example, 311, 222, 099, 111). When the flag is lowered, the old chime (for clearing a level) from Super Mario Bros. will play as you walk into the castle. Once inside, and the flag is raised, fireworks will go off corresponding with the number repeated on the clock. For example, if the time is 099, then nine explosions will be set off; however, if it is 211, only one will go off. The time will also set off other events, as stated in other cheats listed.