48 CFR §22.103-1

Normal workweek, as used in this subpart, means, generally, a workweek of 40 hours. Outside the United States and its outlying areas, a workweek longer than 40 hours is considered normal if—

(1) The workweek does not exceed the norm for the area, as determined by local custom, tradition, or law; and

(2) The hours worked in excess of 40 in the workweek are not compensated at a premium rate of pay.