Well, I wouldn't go backward or forward entire years lmfao, no real reason to. The further back you go, the exponentially greater the chance of loving up the future. I think it would be incredibly useful from a utilitarian perspective so long as your intelligence is preserved during the transit. Think about it. You could use it to fix small mistakes, say the wrong thing in a social situation? Revert 5 minutes and say something else. It would also be useful for studies, you could attend a lecture, then time travel back to the morning, and not attend the lecture having technically already attended it. Or for that matter, take an exam and bomb it, then revert and re-do it with the correct knowledge.