# What Is Time? Time is the ordering of persistent flow, counted by recurrence. A stable flow registers change by continuing to reconfigure. When records of that reconfiguration recur, the recurrence can be counted. Any recurrent pattern of flow can therefore serve as a clock. Time is the count of such recurrent steps. In this framework, the coordinate $t$ in the equations labels ordered registrations of the changing present. Physical time is the operational order of change.