Each day, at occupancy, the optimal start process adapts the Heating or Cooling Constant. It checks the Zone Temperature at occupancy time. If the Zone Temperature did not reach a value within the range defined by the Temp Differential and the Heating Setpoint or Cooling Setpoint before the occupancy time, the Heating Constant or Cooling Constant is increased. This increase moves the optimal start time closer to the earliest start time defined in the OST object. If the Zone Temperature reached a value within the range defined by Temperature Differential and the Heating Setpoint or Cooling Setpoint prior to occupancy, the Heating Constant or Cooling Constant is decreased. This decrease moves the optimal start time closer to the occupancy start time defined in the Schedule Object.