is selected for involuntary separation, is approved for separation under section 1174a or 1175 of this title, or retires pursuant to the authority provided in section 4403 of the Defense Conversion, Reinvestment, and Transition Assistance Act of 1992 (division D of
[Public Law 102–484];
10 U.S.C. 1293 note) during the six-year period beginning on
October 1, 1993;