Time Machine (Calvin and Hobbes)

This Time Machine takes the form of a cardboard box with the open side up. It should not be confused with a Duplicator or a Transmogrifier, though its appearance is very similar and, like them, it works solely because you want it to.

The Department of Sufficiently Advanced Technology is known to possess a Duplicator that has been used as a Transmogrifier, but it is unknown whether it can be or has ever been used as a Time Machine.