I have my "Down WAN Sites" advanced alert set to trigger/reset only between 6am and 6pm. I found it odd that last night I received an "UP" (reset) alert at 9:20pm. 3 hours and 20 minutes past the Time of Day parameters I have set. The advanced alert Time of Day tab states, "The Alert will only be triggered/reset between these hours." What I speculate is happening is that the Time of Day only evaluates during the trigger.
The WAN site I received the "UP" from at 9:20pm actually went DOWN at 5:32pm. Since 5:32 PM is within the 6am-6pm Time of Day settings, once the device came back UP, it sent the reset (because the trigger occurred during the allowed period).
If the tab states alerts will ONLY be triggered/RESET during these hours, then that is most certainly not true. In my evaluation, if the trigger is observed during the Time of Day, then the reset will be sent...always.