Power Rangers Zeo

The season opens as Master Vile uses the Orb of Doom to reverse the rotation of Earth and turn back time, turning the Rangers into powerless children. While the Alien Rangers and a restored Billy defend the Earth, the children go to different times to retrieve pieces of the Zeo Crystal, which was shattered and scattered throughout time by the Rangers themselves. Upon their return, the Zeo Crystal is reassembled, and its power is used to restore the planet to normal... (powerrangers.com)