This option allows you to arm a rule based on the current time of day. If the time of your PC's clock is between the start and end times specified then rule will be armed and will be triggered as soon as ALL of its Conditions are satisfied.
In the image below you can see the start time is set to 09:00:00 and the end time is 13:00:00. The rule will only be allowed to trigger if the current time on the PC is between 9am and 1pm.
