§ 6123

(a) For purposes of determining compensation for overtime hours in the case of an employee participating in a program under section 6122 of this title - (1) the head of an agency may, on request of the employee, grant the employee compensatory time off in lieu of payment for such overtime hours, whether or not irregular or occasional in nature and notwithstanding the provisions of sections 5542(a), 5543(a)(1) and section (!1) 5544(a) of this title, section 7453(e) of title 38, section 7 of the Fair Labor Standards Act (29 U.S.C. 207), or any other provision of law; or (2) the employee shall be compensated for such overtime hours in accordance with such provisions, as applicable. (b) Notwithstanding the provisions of law referred to in subsection (a)(1) of this section, an employee shall not be entitled to be compensated for credit hours worked except to the extent authorized under section 6126 of this title or to the extent such employee is allowed to have such hours taken into account with respect to the employee's basic work requirement. (c)(1) Notwithstanding section 5545(a) of this title, premium pay for nightwork will not be paid to an employee otherwise subject to such section solely because the employee elects to work credit hours, or elects a time of arrival or departure, at a time of day for which such premium pay is otherwise authorized, except that - (A) if an employee is on a flexible schedule under which - (i) the number of hours during which such employee must be present for work, plus (ii) the number of hours during which such employee may elect to work credit hours or elect the time of arrival at and departure from work, which occur outside of the nightwork hours design