14 C.F.R. § 135.265 : Aeronautics and Space — FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION — AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS — OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT — CREWMEMBER FLIGHT TIME AND DUTY PERIOD LIMITATIONS AND REST REQUIREMENTS — Flight time limitations and rest requirements: Scheduled operations

(a) No certificate holder may schedule any flight crewmember, and no flight crewmember may accept an assignment, for flight time in scheduled operations or in other commercial flying if that crewmember's total flight time in all commercial flying will exceed-
(1) 1,200 hours in any calendar year.
(2) 120 hours in any calendar month.
(3) 34 hours in any 7 consecutive days.
(4) 8 hours during any 24 consecutive hours for a flight crew consisting of one pilot.
(5) 8 hours between required rest periods for a flight crew consisting of two pilots qualified under this part for the operation being conducted.
(b) Except as provided in paragraph (c) of this section, no certificate holder may schedule a flight crewmember, and no flight crewmember may accept an assignment, for flight time during the 24 consecutive hours preceding the scheduled completion of any flight segment without a scheduled rest period during that 24 hours of at least the following:
(1) 9 consecutive hours of rest for less than 8 hours of scheduled flight time.
(2) 10 consecutive hours of rest for 8 or more but less than 9 hours of scheduled flight time.
(3) 11 consecutive hours of rest for 9 or more hours of scheduled flight time.
(c) A certificate holder may schedule a flight crewmember for less than the rest required in paragraph (b) of this section or may reduce a scheduled rest under the following conditions:
(1) A rest required under paragraph (b)(1) of this section may be scheduled for or reduced to a minimum of 8 hours if the flight crewmember is given a rest period of at least 10 hours that must begin no later than 24 hours after the commencement of the reduced rest period.
(2) A rest required under paragraph (b)(2) of this section may be scheduled for or reduced to a minimum of 8 hours if the flight crewmember is given a rest period of at least 11 hours that must begin no later than 24 hours after the commencement of the reduced rest period.
(3) A rest required under paragraph (b)(3) of this section may be scheduled for or reduced to a minimum of 9 hours if the flight crewmember is given a rest period of at least 12 hours that must begin no later than 24 hours after the commencement of the reduced rest period.
(d) Each certificate holder shall relieve each flight crewmember engaged in scheduled air transportation from all further duty for at least 24 consecutive hours during any 7 consecutive days.

14 C.F.R. §135.265