Factories Act, 1934 — section 38

38. Spread over..—_The periods of work of an adult worker in a factory shall be so arranged that alongwith his intervals for rest under section 37, they shall not spread over more than 3[twelve] hours in any day, save with the permission of the 4[Provincial Government] and subject to such conditions as it may impose, either generally or in the case of any particular factory.