Any persons elected to a part-time public office or appointed to a part-time elected public office shall be entitled to a leave of absence from his or her private employment except when such employment is with an employer employing five or fewer persons on a full-time basis on the days or portion of any day during which he or she is engaged in performing the duties of his or her public office. The leave of absence shall not result in any penalty being imposed upon the persons entitled to the leave of absence: Provided, That such leave of absence may be without pay by the private employer.