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"close an app" is open to interpretation. The Flash operations will perhaps give you some insight into what is happening.
Profile: Astart
Day: Mon, Tue, Wed, Thu or Fri
Time: From 8:00AM Till 8:01AM
Enter: Anon
A1: Flash [ Text:START 1 Long:Off ]
A2: Launch App [ App:Calculator Data: Exclude From Recent Apps:On Always Start New Copy:Off ]
A3: Flash [ Text:START 2 Long:Off ]
Profile: Astop
Day: Mon, Tue, Wed, Thu or Fri
Time: From 4:58PM Till 4:59PM
Exit: Anon
A1: Flash [ Text:STOP 1 Long:Off ]
A2: Go Home [ Page:0 ]
A3: Kill App [ App:Calculator Use Root:Off ]
A4: Flash [ Text:STOP 2 Long:Off ]
These will start it at 0800 and end it at 17:00.
(If you don't give the time action a range it imposes some strange restrictions on what is generated. The Start tasks starts at the first second of the range. The Stop task starts at the first second after the range.)
... Thom