(a) A workweek shall mean a regularly recurring period of 168 hours in the form of seven consecutive 24-hour periods. A workweek need not coincide with the calendar week—it may begin any day of the week and any hour of the day. Each workweek stands alone. Once fixed, however, it must remain the same unless any change is intended to be permanent.

(b) Except in section 135.11, overtime shall mean only hours worked in excess of 40 hours in any workweek by an eligible officer or employee. As used in section 135.11, such term shall also include, in the case of an eligible officer or employee whose basic work schedule is less than 40 hours per week, hours worked in excess of 37 ½ hours but not in excess of 40 hours in a workweek.

(c) An eligible officer or employee shall mean any officer or employee who is not deemed ineligible to earn overtime pay, as provided under section 135.2.

(d) Scheduled overtime shall mean overtime which is susceptible to scheduling and approval in advance of need.

(e) Unscheduled overtime shall mean overtime which is necessitated by emergency conditions which cannot be anticipated in advance.