I have been thinking about this some more and taking into account the replies so far as more food for thought.
I had to make some assumptions. I assume this is without limit. Meaning you can look 5 seconds into the /pastfuture or 5 million years. That you can look into your own past/future, a friends, a strangers, or the world in general terms.
This mean you could spy on conversations - whether past ones or ones to come. You could see winning lottery tickets or find buried treasure.
I am also seeing it as perhaps sitting down in a meditative state while your vision (astral body perhaps) observes things where ever.
I still think I would limit to past though. I would LOVE to see where the Earth is in 10 years, 50, 100, 1000, and so on. But what if 2030 I saw something like the Handmaiden's Tale or Nazi Germany? Or a world full of war and devastation? How would that affect my remaining years of life? Would I lose hope and become suicidal? Course if I saw wonderful good things it could also make those years much better.
I think it comes down to personality and self-control. Some folks could handle the future and their own death (or the deaths of those they love) or have the control to not view it and stick to the more impersonal future.
Now if it was a more temporary thing - like you were given a chance to pick a few time periods and general things - like what would the state of the world be in a century and go out for a 1000 years - or the same backwards ... then I would pick the future.
Anyhow interesting to think about.
Unrelated it reminds me of a short story I read where someone had the gift to see into the future only they saw it all the time overlaid on reality. When they looked at people all they saw were rotting corpses and decay. It drove them insane.
