1.Learn the Song of Passing
Travel to Windfall Island and find the dancing man, named Tott, on the western cliff near the town jail. Take out the Wind Waker while standing in front of Tott to trigger a conversation. Tott will then motion the notes of a song with his dance moves. After he has finished dancing conduct the song with the Wind Waker: right, left, down.
If you successfully conduct the song, you will learn the Song of Passing, which allows you to change day into night and vice versa.