29 CFR § 553.201 - Statutory provisions: section 7(k).
(a) Section 7(k) of the Act provides a partial overtime pay exemption for fire protection and law enforcement personnel (including security personnel in correctional institutions) who are employed by public agencies on a work period basis. This section of the Act formerly permitted public agencies to pay overtime compensation to such employees in work periods of 28 consecutive days only after 216 hours of work. As further set forth in § 553.230 of this part, the 216-hour standard has been replaced, pursuant to the study mandated by the statute, by 212 hours for fire protection employees and 171 hours for law enforcement employees. In the case of such employees who have a work period of at least 7 but less than 28 consecutive days, overtime compensation is required when the ratio of the number of hours worked to the number of days in the work period exceeds the ratio of 212 (or 171) hours to 28 days.
(b) As specified in §§ 553.20 through 553.28 of subpart A, workers employed under section 7(k) may, under certain conditions, be compensated for overtime hours worked with compensatory time off rather than immediate overtime premium pay.