14 CFR § 117.13
Flight duty period: Unaugmented operations
July 13, 2020
(a) Except as provided for in §117.15, no certificate holder may assign and no flightcrew member may accept an assignment for an unaugmented flight operation if the scheduled flight duty period will exceed the limits in Table B of this part.
(b) If the flightcrew member is not acclimated:
(1) The maximum flight duty period in Table B of this part is reduced by 30 minutes.
(2) The applicable flight duty period is based on the local time at the theater in which the flightcrew member was last acclimated.