There is no requirement that some employers make timely payment of regular paychecks. For persons, firms or corporations engaged in the operation of any railroad, mine, refinery and work incidental to prospecting for, or the production of, oil and gas, or other factory, mill or workshop, within the state of Wyoming, payment is required on or before the first day of each month, when the wages are earned during the first half of the preceding month ending with the fifteenth day thereof; and on or before the fifteenth day of each month when the wages are earned during the last half of the preceding month.