N.J. Stat. § 40A:9-156
Except as otherwise provided by law, the terms of office of all elective officers in any municipality shall commence at 12 o'clock noon on January 1 next succeeding their election and continue for the terms prescribed by law.
The terms of office of all officers appointed by the mayor or other chief executive officer or by the governing body of any municipality, except to fill vacancies, shall commence on January 1 of the year in which they are appointed and continue for the terms prescribed by law, except that the term of office of the assessor shall commence on July 1 next following appointment and continue for the prescribed number of years.
No appointment of any officer shall be made by the mayor or other chief executive officer or by the governing body of any municipality where the term of the office is to commence after the expiration of the term of the officer making the appointment or of any member of the governing body.
N.J.S. § 40A:9-156