I don't believe that time is actually a thing. Change my mind.
That is like saying Height is not actually a thing.
What we see as height is actually a measurement of something in comparison to something else. The way one does it changes. It may be in Feet. It may be in Meters. It may be in Krogospac, but whatever it is measured in, the idea still exists.
The same applies to time. As I see it, time is a measurement of change. If things were static, I think we would not have any measurement of "time" as one would put it. However, as things change, we measure how quickly or slowly that change occurs.
So, if you believe Change is a thing, then you would believe in the idea that time measures.
What I suppose we mean by time travel is the ability to travel to a former state before certain changes occurred.
We are already traveling through time (though we are traveling forward through time) in that we see progressive changes caused by changes previously.