This version of Superman is from the Elseworlds 'Superman & Batman Generations', a tale which tells the story of Superman and Batman in a continuity without a sliding time scale. In other words, their super heroic careers spanning over many decades and how the world changes around them.
In this continuity, young Clark made his debut as Superboy in 1920 and continued his decades of crime fighting right the way into 2919 and beyond with his best friend, Bruce Wayne, keeping pace the whole way. Largely based on the Silver Age Superman, his adventures are hardly grounded in reality but are quite fantastic nonetheless.
Brief timeline; Any Golden Age, Silver Age or Bronze Age story in which Superman appears that does not directly contradict the following is assumed to have occurred.
( Spoilers below. )
In this continuity, young Clark made his debut as Superboy in 1920 and continued his decades of crime fighting right the way into 2919 and beyond with his best friend, Bruce Wayne, keeping pace the whole way. Largely based on the Silver Age Superman, his adventures are hardly grounded in reality but are quite fantastic nonetheless.
Brief timeline; Any Golden Age, Silver Age or Bronze Age story in which Superman appears that does not directly contradict the following is assumed to have occurred.
( Spoilers below. )