time dilations exist, and they can be described from two points of view. Globally, as assuming a 'whole common universe' same for us all, the 'place' in where we live. From that point of view a 'time dilation' is observer dependent, related to mass, 'energy' and (relative) motion, as well as accelerations/decelerations. So they measurably 'exist', but related to you measuring. If all objects in a universe only had (relative) uniform motion accessible, they would still exist, and using Damocles definition, also being 'real', not a illusion. From that point of view the other definition, using 'locality' makes sense too. That as you from that point of view do have a unchanging arrow locally, related to your life span. Nothing you do will change that measurably and locally, as I think. But from that point of view 'frames of reference' becomes something 'real' in themselves, and the commonality of a 'same universe' questionable.

But it is still the simplest approach I've found. And it defines a arrow that points one way, not ticking backwards. You can't even find a arrow tick backwards astronomically, comparing your clock to a event horizon. The best you will find is a definition of some other frame 'stopping to tick' relative your own clock. Mathematically you labor with time reversibility, and treat a arrow by itself. Einsteins definition though, is one in where the arrow is one of four 'real' dimensions called SpaceTime, all dimensions 'fused/joined' together. You tweaking one parameter by mass or motion should then have a effect on the other, which it has, although when it comes to 'length, width and height' they all goes together. You can separate a 'space' theoretically into three dimensions, but you can't do it practically. Using 'degrees of freedom' instead of dimension you can define a two dimensional lattice, the atoms losing one (direction) degree of freedom, but in reality all such 'systems' still are embedded in a four dimensional reality called SpaceTime. Using such a definition ('fused together' dimensions) and also imagining a arrow to tick backwards, what result would that have on the other three dimensions?

Degrees of freedom are the better concept to me, though. Dimensions becoming weird in my thoughts.

=

It would be good if you got five, ten minutes (real local time:) to correct spelling etc, before getting your post 'fixed' by eternity

I think TNS, or rather the developers, tested it locally, not really considering locations outside. and slow connections, because the time estimate I see after correcting is not the same as mine. A 'time dilation' possibly