There are really two types of change. One, absolute, or objective, whereby our perception of a summation of it, or rather, our interpretation of others’ awareness of that change. The actual measurement of it, is not included, since let’s say, we try to determine time in a post modern universe, where, you are the lone survivor.
You find an abandoned watch still running, it shows the hour and minute, but nothing else. You do not have a chronograph to even show the day, month, and even less, the year.
In this peculiar world, the only possible approximated time could be one where other people with watches could concur with your watch. This is objective or external measure of relative change.
The other measure is internal in the sense of being able to visualize time as the change your own appearance goes through, for instance if you have reached the post reflective stage of being able to recognize(here is that word again) your own countenance, at differing points in your life, and come to an awareness of change that way. This latter would be much less grounded in concurrency, because other people’s awareness of you would be beset with problems of diminishing recognition.
The problem with time is, that if it is transmuted to the concept of change, then in essence it is no longer time, as we have come to internalize it, because time MEANS time and CHANGE means change. We have meaning and usage differences, the mean different things, ideas. Therefore, I concur , time does not ‘exist’.
Parmenides even goes as far as to assert that even change is only appearantly so.