N.H. Rev. Stat. Ann. § 541-A:20

After the enactment and before the effective date of any statute granting rulemaking authority, the agency to whom such authority is granted may initiate procedures to adopt such rules; provided that the effective date of the rule, under RSA 541-A:14, IV or RSA 541-A:19, X shall not occur before the effective date of the act granting statutory authority for that rule.