Final answer:
The Active-Duty Service Date (ADSD) marks the beginning of a military member's full-time service in the U.S. Armed Forces, which is important for calculating benefits and retirement eligibility.
Step-by-step explanation:
The Active-Duty Service Date (ADSD) is a specific term referring to the date on which a person begins active duty in one of the branches of the U.S. Armed Forces. This is distinct from the individual's enlistment date for reservists or guard members, as it marks the beginning of their full-time service commitment.
The ADSD is crucial for determining benefits, retirement eligibility, pay raise increments, and overall seniority. When someone enlists and goes through initial training, that period is typically counted towards their ADSD.