1. Notwithstanding the provisions of subsection 1 of section 105.270, any officer or employee of this state, or of any department or agency of this state, or of any county, municipality, school district or other political subdivision, and any other public employee of this state, who is or may become a member of the National Guard or of any reserve component of the Armed Forces of the United States and who is engaged in the performance of duty in the service of the United States under competent orders for an extended and indefinite period of time, shall be entitled to leave of absence from his respective duties as a public officer or employee until such military service is completed without loss of position, seniority, accumulated leave, impairment of performance appraisal, pay status, work schedule including shift, working days and days off assigned to the officer or employee at the time leave commences, and any other right or benefit to which the officer or employee is entitled, and no retirement benefit shall be diminished or eliminated because of such service.

2. The officer or employee shall file with the appointing authority or supervising agency an official order from the appropriate military authority as evidence of such duty for which the leave of absence is granted.