In response to what I wrote there, Dave Matson asked:
Why should time be defined in terms of relativity physics where, presumably, it means a fixed future? I would think that time, as defined in quantum mechanics, would be equally preferable. As defined in this latter sense, time is presumably compatible with an undetermined future.
If we accept time as defined in relativity, then it seems that physicists would have to accept that there are "wheels within wheels" within quantum mechanics, which most physicists deny. That denial suggests that time as seen in quantum mechanics is defined differently than in relativity physics. One view seems compatible with a fixed future whereas the other does not obviously fit into that mold, if at all.
So arguing for a fixed future on the basis of relativity theory is tantamount to assuming that its definition of time should be preferred. Therein, I see a problem.
In answering this question I will use RT for Relativity Theory and QM for Quantum Mechanics. And I will not repeat what I said in my book. So if you haven't read it, though you don't have to in order to understand what follows, you probably should read it before commenting on any of this.