Evidence of age required for certain enlistments of minors No minor may be enlisted in the Kegular Navy as a seaman, seaman apprentice, or seaman recruit, unless he shows that he is of an age eligible under regulations to enlist by presenting to the recruiting oflBlcer, with his application for enlistment— (1) a birth certificate; (2) a verified written statement by either parent; or (3) a verified written statement by his legal guardian, if his parents are dead. However, if such a certificate or statement is unobtainable, a minor may be enlisted in such a grade if the recruiting officer is convinced that the oath of the applicant as to his age is credible. § 5536. Extension: time lost through misconduct or unauthorized absence (a) If an enlisted member of the naval service is unable to perform his duties for a period of more than one day because of injury, sickness, or disease resulting from his intemperate use of drugs or alcoholic liquor or from other misconduct, his enlistment is extended by the amount of time so lost. (b) A n enlisted member of the naval service who for a period of more than one day— (1) is absent from his station and duty without proper authority; (2) is confined under sentence; or (3) is confined while awaiting trial and disposition of his case, if his trial results in conviction; may be permitted to serve after his return to a full duty status for a period that, when added to the time that he served before such absence or confinement, amounts to the full term of his enlistment. § 5537. Extension: during disability incident to service A n enlisted member of the naval service on active duty whose term of enlistment expires while he is suffering from disease or injury incident to service and not due to his misconduct, and who needs medical care or hospitalization, may be retained on active duty, with his consent, until he recovers to the extent that he is able to meet the physical requirements for reenlistment or until it is determined that recovery to that extent is impossible. § 5538. Extension: during war or national emergency (a) The Secretary of the Navy may extend enlistments in the Regular Navy and the Regular Marine Corps in time of war or in time of national emergency declared by the President for such period as he considers necessary in the public interest. Each member whose enlistment is extended under tms section shall be discharged not later than six months after the end of the war or national emergency, unless he voluntarily extends his enlistment. (b) The substance of this section shall be included in the enlistment contract of each person enlisting in the Regular Navy or the Regular Marine Corps.