N.J. Stat. § 18A:25-3: Teaching, etc., on holidays not required

No teaching staff member shall be required to perform his duties on any day declared by law to be a public holiday and no deduction shall be made from such member's salary by reason of the fact that such a public holiday happens to be a school day and any term of any contract made with any such member which is in violation of this section shall be void.

L.1967, c.271.