This is a PowerPoint presentation on timers for your center rotations. The clean-up is set to come on 18 minutes after the center starts. The children know that it is clean-up time because of the Star Wars transition music. Each group has a color so that you can see that they hit the different centers. The white means that there is no one at that center at that time. It is completely customizable. You can change the timings, the music, the numbers of centers, the titles of the centers, etc.