Time is not a tangible. It is neither a field nor a fabric. Time is simply a measurement, the comparison of two or more rates of change. It is much like comparing distances with a ruler, but instead of evaluating an unknown length against a standard unit, you are measuring the amount of change occurring within one sequence against the progress of some other standard event like the rotation of a planet or the vibration of a cesium atom.
The rate at which material things can change or be changed seems to be affected by their proximity to other mass-laden objects. Orbiting in space - in the absence of gravitational attraction - the internal rate of change of a clock synchronized with an identical earth-bound clock runs faster than its terrestrial twin. It seems gravity causes some form of drag on rates of change. There also seems to be a natural limit to the rate at which material things can change that is directly related to the speed of light. At a low relative velocity compared to an observer, a clock may seem to keep perfect time, but as it approaches the speed of light, its rate of change declines and the clock ticks ever more slowly until it stops. Nature somehow seems to impose a balance or a limit on total rates of change with a trade-off between the speeds of external and internal processes. Interesting, isn't it?
The concept of time has been highly over-mystified due to the illusion imposed upon our thinking by the phenomenon of memory. By engaging our memories, we can conceptually revisit past events. Time is nothing more than change, and though some changes can be reversed, to actually go back in time it would first be necessary to halt all processes in the Universe and then successfully apply an omnificent force to reverse them throughout the cosmos. But even such an extraordinary procedure would not turn back the course of time. Whatever process was engaged to controvert time would also have to CEASE acting at the same temporal point it began - for if it progressed, so would time.
On the other hand, it is easy to travel - and even accellerate into - the future. You do it once a day. It is called sleep. While you sleep, your internal metabolism slows down. When your internal rate of change slows relative to your surroundings, time passes more quickly and hours seems to fly by in mere minutes.
Mathematically it may be convenient and even expedient to consider time as a dimension, but other than the physical changes it measures, it has no location, no attributes, no separate existence or reality of its own. The term 'dimension' is best left to describing spatial relationships.