Example 1: A 20-day rental agreement commences September 2nd and expires on September 22nd. The entire rental agreement period falls within the quarter ending September 30th, so that the return with payment of fees must be filed by the end of the month following that quarter (that is, by October 31st).
Example 2: A 20-day rental agreement commences September 22nd and expires on October 12th. Although eight days of the rental agreement fall within the quarter ending September 30th, the return with payment of fees for the entire 20-day rental period accrues in the quarter for October 1st through December 31st, and is not required to be filed until the end of the month following that quarter (that is, by January 31st of the following year).
N.J. Admin. Code § 18:40-1.10