When you open the game click on "New Game" or "Continue" to begin a night. When you enter the night you want to skip simply hold down the buttons "C" "D" and "+ (On the Num-pad)" at any time of the night and you will see the timer go from 5 AM to 6 AM.

When you open the game simply hold down "C" "D" and "1" at the title screen.

When you open the game simply hold down "C" "D" and "2" at the title screen.