Time is indeed a concept and not a real entity as existential events invoke time. What one sees on a clock is the real representation of conceptual time.
Moreover, time does not occupy any of the three perceptible dimensions of space - length, breadth, depth - rather time can prevail in imperceptible, fourth dimensional state, when a lower, three dimensional reality within space would have no influence on time, only such three dimensional existential events can invoke time. The succession of time is irreversible, independent from any external, existential influence within three dimensional space.
Time is more of an abstract concept; like the abstraction in Mathematics - the process of extracting the underlying structures, patterns or properties of a mathematical concept, removing any dependence on real world objects with which it might originally have been connected.
It is wrong to interpret that Time is a real thing. Rather time is a concept.
Read What was there before the Big Bang?