The Alarm Action condition "time of day is between" states a time period between today and the following day when an action is supposed to be performed. Outside of that time, nothing will be done.
Given the time frame of 8:00 PM to 6:00 PM means that from 8:00 PM today to 6:00 PM tomorrow, an action will fire. Between 6:01 PM to 7:59 PM, nothing will be done.
Note: The time used is the time of the Diagnostic Server host and not the time of the monitored instances.
