(1) An employee's workweek is a fixed and regularly recurring period of 168 hours -seven consecutive 24 hour periods. It need not coincide with the calendar week but may begin on any day and at any hour of the day. For purposes of computing pay due under the Montana Minimum Wage Law, a single workweek may be established for a plant or other establishment as a whole or different workweeks may be established for different employees or groups of employees. Once the beginning time of an employee's workweek is established, it remains fixed regardless of the schedule of hours worked by him. The beginning of the workweek may be changed if the change is intended to be permanent and is not designed to evade the overtime requirements of the Law. The proper method of computing overtime pay in a period in which a change in the time of commencement of the workweek is made, is discussed in subsections (1) and (2) of ARM 24.16.2531.
(2) There is no requirement in the Law that overtime compensation be paid weekly. The general rule is that overtime compensation earned in a particular workweek must be paid on the regular pay day for the period in which such workweek ends. When the correct amount of overtime compensation cannot be determined until some time after the regular pay period, however, the requirements of the Law will be
satisfied if the employer pays the excess overtime compensation as soon after the regular pay period as is practicable. Payment may not be delayed for a period longer than is reasonably necessary for the employer to compute and arrange for payment of the amount due and in no event may payment be delayed beyond the next day after such computation can be made. Where retroactive wage increases are made, retroactive overtime compensation is due at the time the increase is paid.