(a)(1) Not later than 6 months after the effective date of this Act [Sept. 15, 1981], all officers of the Army, Navy, Air Force, and Marine Corps who are required to be placed on the active-duty list for their armed force under chapter 36 of title 10, United States Code, as added by this Act, shall be placed on such list with the same relative seniority which they held on the day before the effective date of this Act. An officer placed on an active-duty list under this section shall be considered to have been placed on such list as of the effective date of this Act.
“(2) Regulations prescribed under section 620 of title 10, United States Code, as added by this Act, shall be applicable to the placement of officers on the active-duty list under paragraph (1).
“(b) Under regulations prescribed by the Secretary of Defense, which shall apply uniformly among the Army, Navy, Air Force, and Marine Corps, the Secretary of the military department concerned, in order to maintain the relative seniority among officers of the Army, Navy, Air Force, and Marine Corps as it existed on September 14, 1981, may adjust the date of rank of officers—“(1) below the grade of brigadier general or commodore during the one-year period beginning on September 15, 1981; and
“(2) above the grade of colonel or, in the case of the Navy, captain until there are no longer any officers to whom section 614(d) is applicable.