(a) For the purpose of determining whether an enlisted member of the Army may be retired under section 7314 or 7317 of this title, his years of service are computed by adding all active service in the armed forces and service computed under section 3683 ¹ of this title.

(b) Time required to be made up under section 972(a) of this title may not be counted in determining years of service under subsection (a).