Sec. 4.02. MILITARY SERVICE. A member of the fund retains all accumulated service credit and is allowed service credit for each month during which the member leaves employment with the fire department and performs active duty service in the armed forces or the armed forces reserves of the United States or their auxiliaries, except that:

(1) the military service credit may not be for more than five years and the person must return to service with the fire department not later than the 180th day after the date of discharge or release from military service or from hospitalization continuing after discharge for a period of not more than one year;

(2) the member must leave the member's contributions in the fund during the period of absence; and

(3) the member must file a written application with the fund for the military service credit, accompanied by satisfactory proof of the member's military service.