A member of a fire department or district who has served as a member of the military establishment of the United States during a period of national emergency, immediately following service as a member of the fire department or district, shall not be required to contribute to the fire fighters' relief and pension fund by salary deduction or otherwise for the period during which the member was in military service. The period of military service shall be included in computing the length of service of the firemen in determining eligibility for retirement.
A.R.S. § 9-970