Every employee of the State or any political subdivision thereof who, on or after June 25, 1950 has been, or shall be, commissioned, enlisted or selected for service in the armed forces of the United States shall, so long as the requirements and regulations of the armed forces shall prevent his return to his civil employment and for a period of ninety days thereafter, but in no event for a period longer than five years from the date of his entry into the armed forces of the United States, be entitled to leave of absence from his duties as an employee of the State or any political subdivision thereof, without loss of seniority or efficiency or register rating.

The word "employee" as used herein shall not be construed to mean an officer or official elected or appointed to a term pursuant to a statute or the Constitution of this State.