In the movie Superman (1978), Superman flies around the world in one direction to make the Earth go back in time, and then he stops and then flies around the Earth in the opposite direction to restore the Earth back to its normal timeline.
At the moment when the Earth is temporarily back in time, I believe that there is one Superman who is down on Earth who is fixing the damaged San Andreas fault line, and there is another Superman who is up in outer space above the Earth, who is about to start flying again to restore the Earth back to its normal timeline.
Did two Supermans exist at this point in time?