Time Travel is the concept of movement between different points in a manner analogous to moving between different points in space. Barry Allen is capable of using his Super Speed and connection to the Speed Force to run so fast he can move between points in time.
In an alternate timeline, Barry Allen uses the Speed Force to travel back in time to warn Bruce Wayne to find Lois Lane and prevent Superman from taking over the Earth. He arrives in 2015 which is 'too soon' as Bruce doesn't fully understand the message and Barry departs.
- Batman v Superman: Dawn of Justice (First appearance)