; (2) in subsection (b), by striking when he and inserting when the warrant officer ; and (3) in subsection (c)— (A) by striking as he and inserting as the Secretary concerned ; and (B) by striking after he and inserting after the warrant officer . 513. Flexibility in determining terms of appointment for certain senior officer positions (a) In general Chapter 35 of title 10, United States Code, is amended by inserting after section 601 the following new section: 602. Flexibility in determining terms of appointment for certain senior officer positions The Secretary of Defense may extend or reduce the duration of an appointment made under section 152, 154, 7033, 8033, 8043, 9033, and 9082 of this title by up to six months if the Secretary determines that such an extension or reduction is necessary either in the interests of national defense, or to ensure an appropriate staggering of terms of senior military leadership. . (b) Clerical amendment The table of sections at the beginning of chapter 35 of title 10, United States Code, is amended by inserting after the item relating to section 601 the following new item: 602. Flexibility in determining terms of appointment for certain senior officer positions. . B Reserve component management 521. Alternative promotion authority for reserve officers in designated competitive categories (a) In general Part III of subtitle E of title 10, United States Code, is amended by adding at the end the following new chapter: 1413 Alternative promotion authority for officers in designated competitive categories Sec. 15101. Officers in designated competitive categories. 15102. Selection for promotion. 15103. Eligibility for consideration for promotion. 15104. Opportunities for consideration for promotion. 15105. Promotions. 15106. Failure of selection for promotion. 15107. Retirement: retirement for years of service