There's really no such thing as "time" right? Clocks don't actually measure time, they measure change, correct? There are predictable things that happen at determined intervals such as sunrise and sunset cycles, tides, etc., and clocks are useful measuring devices to indicate to us when these cycles will occur? I would think calendars also apply as measurements of time, but more relative to seasons than events. Otherwise, there's not really such a thing as time, there's only perpetual existence I'm thinkin'.