New Jersey Statutes Title 40A. Municipalities and Counties 40A § 16-21

All appointees to fill a vacancy, whether to fill the unexpired term or temporarily, shall take office immediately after appointment and qualification. All persons elected to serve for the unexpired term of an office shall take office immediately upon certification of the results of the election pursuant to the provisions of R.S. 19:20-9. All persons elected to serve for a full term of office shall take office on the date fixed for the commencement of the term of the office.