5 CFR § 610.102 - Definitions.
In this subpart:
Regularly scheduled administrative workweek, for a full-time employee, means the period within an administrative workweek, established in accordance with § 610.111, within which the employee is regularly scheduled to work. For a part-time employee, it means the officially prescribed days and hours within an administrative workweek during which the employee is regularly scheduled to work.
Tour of duty means the hours of a day (a daily tour of duty) and the days of an administrative workweek (a weekly tour of duty) that constitute an employee's regularly scheduled administrative workweek.