5 U.S.C. § 6126

1. (a)Subject to any limitation prescribed by the Office of Personnel Management or the agency, a full-time employee on a flexible schedule can accumulate not more than 24 credit hours, and a part-time employee can accumulate not more than one-fourth of the hours in such employee’s biweekly basic work requirement, for carryover from a biweekly pay period to a succeeding biweekly pay period for credit to the basic work requirement for such period.
2. (b)Any employee who is on a flexible schedule program under section 6122 of this title and who is no longer subject to such a program shall be paid at such employee’s then current rate of basic pay for—
   1. (1)in the case of a full-time employee, not more than 24 credit hours accumulated by such employee, or
   2. (2)in the case of a part-time employee, the number of credit hours (not in excess of one-fourth of the hours in such employee’s biweekly basic work requirement) accumulated by such employee.