During a national emergency declared by the President, the regular working hours of laborers and mechanics of the Department of the Air Force producing military supplies or munitions are 8 hours a day or 40 hours a week. However, under regulations prescribed by the Secretary of the Air Force these hours may be exceeded. Each laborer or mechanic who works more than 40 hours in a workweek shall be paid at a rate not less than one and one-half times the regular hourly rate for each hour in excess of 40.