In the Balloon Garden booth, you will come to the Garden Grown mini game.
You will notice a set of three clouds with three rain drop balloons attached to them. Pop the all the rain drops on the clouds. A little before the level is over, another cloud will come from the top right of the screen. Pop the three rain drops on that cloud, and the sky will change from day to night.
Video Credit goes to OnceFallenPS3T