N.Y.C. Admin. Code § 20-916: § 20-916 Collective bargaining agreements.

a. The provisions of this chapter shall not apply to any employee covered by a valid collective bargaining agreement if (i) such provisions are expressly waived in such collective bargaining agreement and (ii) such agreement provides for superior or comparable benefits for the employees covered by such agreement in the form of paid or unpaid time off; such time off shall be in the form of leave, compensation, other employee benefits, or some combination thereof. Comparable benefits shall include, but are not limited to, vacation time, personal time, and holiday and Sunday time pay at premium rates, provided however that unpaid time off shall not be considered a comparable benefit for purposes of paid safe/sick time or paid prenatal leave under section 20-913.

b. Notwithstanding subdivision a of this section, the provisions of this chapter shall not apply to any employee in the construction or grocery industry covered by a valid collective bargaining agreement if such provisions are expressly waived in such collective bargaining agreement.