Actually time may be the only thing that is constant. Not the measuring of time. Not the passage of time. Just time itself. Everything else is a construct of time. There has never been a time when there was no time. We're just passing through time, however small or large you choose to measure, time is constant. Time does not move. We do.
On the other hand, time itself may be a fundamental specific attribute of every existing thing. Local to everything at the point it starts to exist. So that any thing coming into existence and all of the time associated with it, are conterminous.
Not constant then, but only time itself occurs when some thing happens, or some things happen.
