Planetarium Doraemon: Jikan no Himitsu

After arriving late at school, Nobita comes up with what seems like the perfect solution: get rid of clocks and sleep for as long as he likes. With Doraemon's help, he uses the What-If Box to create a world without ticking clocks. Yet he still oversleeps and arrives late. People simply keep track of time through sunrise, sunset, and the changing position of shadows.

Still determined to find a way to sleep without ever being late, Nobita uses a learning kit about the universe's creation and discovers how closely time and the universe are connected. Then a parcel of time-related gadgets arrives from the Future Department Store, and one of them causes serious trouble.