N.J. Stat. Ann. § 43:13-22.15a

Notwithstanding the provisions of the act to which this act is a supplement limiting the time within which applications for membership in the retirement system were required to be made, all present employees of the city who are otherwise eligible for membership may make application for, and be admitted to, membership in the retirement system upon declaration of intention in writing made to the commission within 3 months of the effective date of this act or within the time prescribed by the act to which this act is a supplement, whichever is later.