Whenever I think along these lines, I can never reconcile it with relativity, and the fact that gravity effects time. If it's just a human construct, how can it be effected by gravity?
It reminds me of the Plank (sp) constant, a minimum unit of distance (? unsure if I remember / ever understood this correctly).
A pure (parallel) event driven model of time might be seen as the propagation of energy with some form (information). In that model folded dimensions, gravity, even the concept of space or time can distort as relationships strain. That's how space and time could be 'affected by gravity'.
Yet even with that framework I can't imagine time travel anywhere remotely like it exists in fiction. I would really like to think that it's just my very non-expert knowledge, and the general immaturity of even our knowledge as a species that keeps the universe such a mundane place. Any form of FTL, time travel, or similar fun scifi concept would keep life interesting.
?? Given that photons which transmit energy are 'timeless' that's a strange claim.
Understanding Relativity means embracing certain paradoxes and that just happens to be one of them. I mean yes, absolutely, the world of a photon would be something akin to a mathematical point with no distance or time. That knowledge is important but it's not always useful.