5 CFR § 550.1304
Overtime hourly rates of pay
November 4, 2020
(a) For a firefighter who is covered by (i.e., nonexempt from) the overtime provisions of the Fair Labor Standards Act (FLSA), the overtime hourly rate of pay equals 11⁄2 times the firefighter hourly rate of basic pay for that firefighter, as established under §550.1303(a) and (b)(2).
(b) For a firefighter who is exempt from the FLSA, the overtime hourly rate is computed as provided in §550.113(e).
(c) For any firefighter, overtime pay for any pay period is derived by multiplying the applicable overtime hourly rate by all overtime hours within that period.