Well, to me, time is a pendulum, hanging in stasis. It swings once, and then when it swings back, everything is undone. But for each swing of the pendulum, time changes slightly. This means that all time has existed before and after. So, theoretically, if you time travel, you just travel to another of the pendulum lifestyles and experience it there. Meanwhile, another version of you is created, the pendulum stops to fix things, and then continues on.