An occupancy sensor is provided with a separable override unit which can selectively override the operation of the occupancy sensor at designated times and for selected time intervals. The occupancy sensor includes a light sensor for actuating the occupancy sensor and a light assembly when the ambient light is below a predetermined level and to deactivate the occupancy sensor when the ambient light is above a threshold level to prevent the light assembly from being actuated when the light level is sufficient to avoid the need for actuating the light assembly. The override unit is removably attached to the occupancy sensor and is provided with a light source, such as an LED. The override unit is coupled to the occupancy sensor to emit light to actuate the light sensor of the occupancy sensor, thereby controlling the operation of the occupancy sensor, such as by preventing the occupancy sensor from being actuated regardless of the light level in the surrounding areas. The occupancy sensor includes a cavity on a top surface for receiving the override unit. The light sensor of the occupancy sensor is positioned in the cavity. The LED on the override unit in on an end that is inserted into the cavity to align with the light sensor. A control unit is operatively connected to one or more override units for selectively controlling the normal operation of the occupancy sensor.