Unless otherwise provided by law, all officers and employees of state agencies, boards, commissions, departments and institutions authorized by law to receive per diem compensation for each day or fraction thereof occupied with the discharge of official duties shall be entitled to Forty Dollars ($40.00) per diem compensation. When the Governor, Lieutenant Governor or Speaker of the House of Representatives appoints a person to a board, commission or other position that requires confirmation by the Senate, the person may receive per diem compensation for the performance of official duties before such appointment is confirmed by the Senate, as such per diem compensation is authorized under this section.