on the question of time

It's been a while since I posted here but let me try an idea out. I have been looking at the question of time. Not the mathematical time used by the Einsteins and other mathematical geniuses, but the time used by all the rest of us. My thought is that it doesn't exist. Time, as measured on a clock, is a false image. It is just a measurement of what we see as change and it is not always accurate as to the rate at which change is occuring. Millenia, centuries, decades, years, months and days do not exactly fit to the moments of change. And how long would a light year be if we lived on Mars?