Incident report SLA calculation w.r.t criticality and calculating business hours or not

Critical (P1)30 Mins (BH) 120 Mins(NBH)
High (P2) 60 Mins (BH) 240 Mins(NBH)
Average (P3) 90(BH) 360 Mins(NBH)
Low(P4) 120 Mins (BH) 480 Mins(NBH)

Business Hours is 0800 hrs - 2000 hrs

In the attached excel sheet have to define column I as BH or NBH with reference as call open time and classify SLA breached as true or false according to priority and when the call was logged whetehr in BH or in NBH.