Let me ask again, more specifically: What observable property, geometic or otherwise, does time have? Also again, I am not denying the relativity's procedures for expressing events in another frame in terms of the variables of your frame. I am saying that in any one inertial frame time is just an index, not a dimension. Also I think your "The rate at which time proceeds at any point near a gravitational ..." reflects the false but wide spread idea of "time flowing." What the gravitational field does is make two identical processes not complete simultaneosly, even if started simultaneously. The one in the weaker field completes before the one in the strong field does. Only processes making changes are observable, not time. Physics concerns observables, not fiction like time, that does not exist.