In pertinent part, the version of RSA 677:2 applicable to this case states: Within 30 days after any order or decision of the zoning board of adjustment, . . ., any party to the action or proceedings, or any person directly affected thereby may apply for a rehearing in respect to any matter determined in the action or proceeding, or covered or included in the order, specifying in the motion for rehearing the ground therefore; and the board of adjustment, a board of appeals, or the local legislative body, may grant such rehearing if in its opinion good reason therefor is stated in the motion. This 30-day time period shall be counted in calendar days beginning with the date upon which the board voted to approve or disapprove the application; . . . By the enactment of Chapter 105 of the 2005 Session laws on June 15, 2005, RSA 677:2 was amended to begin the 30-day time period on "the date following the date upon which the board voted to approve or disapprove the application . . ." (Supp. 2005). The statute became effective August 14. 2005. Id. In New Hampshire, statutes "affecting procedural or remedial rights are usually deemed to apply retroactively to accrued cases not yet filed or those pending cases which on the effective date of the statute have not vet gone beyond the procedural stage to which the statute pertains." In re Beauregard, 151 N.H. 445, 448, 859 A.2d 1153 (2004). This issue involves procedural rights, but has gone beyond the stage at which the petitioners may file a motion for rehearing. Thus, this amendment does not apply retroactively. "The thirty-day time period begins to run on the date of the decision." Pelletier v. City of Manchester, 150 N.H. 687, 689, 844 A.2d 484 (2004). "A timely motion for rehearing 'is a necessary prerequisite to maintenance of an appeal, and to the jurisdiction of the superior court on an appeal."' Id. (quoting Keene v. Zoning Bd. of Adjust., 114 N.H. 744, 746, 329 A.2d 141 (1974)). Even the board hearing the petition cannot waive compliance with these mandatory time limits. See Keene, 114 N.H. at 746; see also Daniel v. B & J Realty, 134 N.H. 174, 176, 589 A.2d 998(1991).