Let's try to clear the confusion here by understanding basics of SF
1. If you are using 24 hr clock, do not specify the "A" or "P" represent AM/PM. So, 18:00P will be invalid, use 18:00 or 6:00P.
2. If you want the start time to be 12:01 after noon, please use either 12:01 or 0:01P
3. If the current time falls within the SF time range, you will see the flag "CLEAR", otherwise it will show "SET"
81 -> 6:00-12:00
82 -> 12:01-18:00 (or 0:01P-6:00P)
83 -> 18:01-23:59 (or you know it by now )
84 -> 0:00-5:59