This read-only TruthValue reports whether the ACE's associated time range is currently active, meaning whether the ACE itself is presently in effect. It gives an admin a real-time way to confirm a scheduled rule is or isn't currently enforcing its action, without having to compute the time range manually. For example, an admin troubleshooting why traffic isn't being blocked at 2am would check this field and see it reads false because the time range only covers business hours.