Sorry boys, forgot to say that client has two gates, and the one I'm trying to automate is the entry one.
Entry gate opens, lights come on for 20-25minutes. Since the gate is on a 90sec auto-close settings, I won't care if the sensor triggers again on gate close. In my case that would mean that my 20min routine would actually stay on for 21.5min. Obviously not a big deal to adjust the timer to compensate for the gate auto-close sensor tripping.