801—16.3 (82GA,HF2283) Definition of active duty. “Active duty” means full-time duty in the armed forces of the United States, excluding active duty for training purposes only and excluding any period a person was assigned by the armed forces to a civilian institution for a course of education or training which was substantially the same as established courses offered to civilians, or as a cadet or midshipman, however enrolled, at one of the service academies.