5 C.F.R. § 550.1403
In this subpart:
Accrued compensatory time off means the compensatory time off earned by an employee that has not been used or forfeited.
Agency means an Executive agency as defined in 5 U.S.C. 105 .
Authorized agency official means the head of the agency or an official who is authorized to act for the head of the agency in the matter concerned.
Compensable refers to periods of time that are creditable as hours of work for the purpose of determining a specific pay entitlement, even when that work time may not actually generate additional compensation because of applicable pay limitations.
Compensatory time off means compensatory time off for travel that is credited under the authority of this subpart.
Official duty station means the geographic area surrounding an employee's regular work site that is the same as the area designated by the employing agency for the purpose of determining whether travel time is compensable for the purpose of determining overtime pay, consistent with the regulations in 5 CFR 550.112(j) and 551.422(d) .
Regular working hours means the days and hours of an employee's regularly scheduled administrative workweek established under 5 CFR part 610.
Scheduled tour of duty for leave purposes means an employee's regular hours for which he or she may be charged leave under 5 CFR part 630 when absent. For full-time employees, it is the 40-hour basic workweek as defined in 5 CFR 610.102 . For employees with an uncommon tour of duty as defined in 5 CFR 630.201 , it is the uncommon tour of duty.
Travel means officially authorized travel-i.e., travel for work purposes that is approved by an authorized agency official or otherwise authorized under established agency policies. Time spent traveling in connection with union activities is excluded.
Travel status means travel time as described in § 550.1404 that is creditable in accruing compensatory time off for travel under this subpart, excluding travel time that is otherwise compensable under other legal authority.
5 C.F.R. §550.1403