The plaintiffs, K & J Associates and Paul Korpela, appeal an order of the Superior Court (Abramson, J.) ruling that because the plaintiffs’ appeal from the decision of the City of Lebanon Planning Board (board) was not timely filed under RSA 677:15 (Supp. 1994) (amended 1995), the court lacked subject matter jurisdiction to hear the appeal. We reverse and remand.
The plaintiffs submitted an application for site plan review of a proposed Wal-Mart retail store to the board. Both plaintiffs’ counsel and a representative of the plaintiffs attended the final meeting on the application on March 24, 1994. At the meeting board member Ron Bailey moved to deny approval of the application. Bailey read a written draft of the motion and proposed determinations into the record. The motion recited the reasons for the denial and referred to two further pages of documentation attached to the motion. In a recorded vote, the board voted 7-0 (with one abstention) to grant Bailey’s motion and deny the plaintiffs’ application.
At the close of the meeting, the board’s chairman, Norman Dobson, gave the motion regarding the application and attached documentation to. the board’s recording secretary, Tracy Colburn. She took the motion and other papers home that night. The following day, March 25, 1994, Colburn brought the motion and papers to the planning department office. She reviewed the motion, meeting tape, and her notes, and compiled a draft Notice of Action as required by the site plan review regulations of the City of Lebanon. The Notice of Action incorporated the motion and confirmed the board’s denial of the plaintiffs’ application. Colburn then phoned Dobson to request that he review and sign the Notice of Action. Later that day, a representative of the plaintiffs came to the office to request a copy of the board’s decision. Colburn provided him with either a copy of the adopted motion or an unsigned copy of the Notice of Action.
On March 28, 1994, Dobson signed the Notice of Action. On March 29, 1994, Colburn sent a signed copy of the Notice of Action to the plaintiffs’ representative in accordance with the Lebanon site plan regulations. On April 26, 1994, the plaintiffs filed a petition, in the superior court to review the board’s decision pursuant to RSA 677:15.
The superior court sua sponte raised the issue of the timeliness of the appeal. After a hearing, the court dismissed the appeal on the *333basis that it lacked subject matter jurisdiction because the plaintiffs’ petition was filed after the statutory thirty-day appeal period had run.
The issue of subject matter jurisdiction may be raised at any time in the proceedings. See In Re Net Realty, 127 N.H. 276, 277, 497 A.2d 865, 866 (1985). “[C]ompliance with the procedural deadline for filing an appeal is a necessary prerequisite to establishing jurisdiction in the appellate body.” Dermody v. Town of Gilford, 137 N.H. 294, 296, 627 A.2d 570, 571 (1993) (emphasis omitted). If the plaintiffs did not appeal the board’s decision within the thirty-day period prescribed by RSA 677:15, I, then the superior court properly dismissed the action for lack of subject matter jurisdiction. See id.
The plaintiffs challenge the superior court’s ruling that the thirty-day appeal period began to run on March 25, 1994 — that is, when Colburn placed the materials relevant to the planning board decision in the planning office and made them available to the public. At issue is the prior version of RSA 677:15, I, which stated:
Any persons aggrieved by any decision of the planning board concerning a plat or subdivision may present to the superior court a petition, duly verified, setting forth that such decision is illegal or unreasonable in whole or in part and specifying the grounds upon which the same is claimed to be illegal or unreasonable. Such petition shall be presented to the court within 30 days after the filing of the decision in the office of the planning board.
RSA 677:15 (Supp. 1994). In interpreting the statute, “this court is the final arbiter of the intent of the legislature as expressed in the words of a statute considered as a whole.” Welch v. Director, N.H. Div. of Motor Vehicles, 140 N.H. 6, 8, 662 A.2d 292, 293 (1995). Where the statutory language is ambiguous or where more than one reasonable interpretation exists, we review legislative history to aid in our analysis. See State v. Telles, 139 N.H. 344, 346, 653 A.2d 554, 556 (1995); Petition of Walker, 138 N.H. 471, 474, 641 A.2d 1021, 1024 (1994).
The word “decision” is undefined in the statute. Under the regulations of the City of Lebanon, however, “the decision of the Board” is reflected in the Notice of Action, which must be “signed by the Chairperson or designee.” CITY OF LEBANON SITE PLAN REVIEW REGULATION 4.5 (adopted June 14, 1988). This signed document, the plaintiffs argue, represents the “decision” that must *334be filed to begin the thirty-day appeal clock ticking. Consequently, under the plaintiffs’ interpretation of “decision,” the appeal period began to run on March 28, 1994, when the Notice of Action prepared by Colburn was signed by Dobson and made available to the public in the planning office. The defendants counter that the appeal period began to run on March 25, 1994, when Colburn filed all of the papers from the previous night’s meeting in the planning office, prepared the Notice of Action, and made these materials available to the public.
“[T]he time for appeal begins to run when the decision is delivered to the official whose duty it is to file it and [the official] pla,ces the decision in the place where such decisions usually are kept.” 4 R. ANDERSON, AMERICAN LAW OF ZONING 3D § 27.24, at 540 (1986). “[I]t may be difficult to establish when a decision was filed with the board,” 15 E LOUGHLIN, NEW HAMPSHIRE PRACTICE, LAND USE PLANNING AND ZONING § 33.02 (2d ed. 1993).
What event triggers the beginning of the appeal period as contemplated in the statute is ambiguous at best. See LaVallee Northside Civ. Ass’n v. Coastal Zone Mgt., 866 F.2d 616, 623 (3d Cir. 1989). Dictionary definitions are unhelpful; the legislative history provides no guidance.
Nor does the amended version of the statute clarify the triggering event for beginning the appeal period. The current version of RSA 677:15, I, states that a petition for appellate review “shall be presented to the court within 30 days after the decision of the planning board has been filed and first becomes available for public inspection in the office of the planning board or its clerk or secretary.” RSA 677:15,1 (1996). The amendment, however, does not shed any light on what the “decision” as contemplated by the statute actually is.
Ambiguities as to whether an appeal is timely are resolved in favor of - the person seeking to review the determination. 4 E. ZIEGLER, RATHKOPF’S THE LAW OF ZONING AND PLANNING § 42.04, at 42-21 (4th ed. 1996). Provisions limiting the time for appeal are based “on the assumption that the public interest will be best served by finalizing the decisions of the board and firming-up the rights to develop land at the earliest moment which is consistent with fair process.” ANDERSON, supra § 27.24, at 532. Nevertheless, the start of the appeal period should not be triggered^ by so imprecise an event that the aggrieved party could effectively be deprived of the right to appeal. To be sure,
*335[a] litigant ought not suffer the consequences of a procedure that is so loose and indefinite. . . . By so holding, we may be doing violence to the English language. On the other hand, not to take an arbitrary stand until the board itself makes it clear to litigants when matters are entered would indeed do violence to the right of review.
Chester Township Bd. of Trustees v. Kline, 249 N.E.2d 921, 924 (Ohio Ct. App. 1969) (quotation omitted).
Because the start of the appeal period in this case is ambiguous, we choose the triggering event that is concise and consistent with fair process — the filing of the signed Notice of Action — and determine that the appeal period began to run on March 28, 1994. See Chadwick v. Gwinnett County, 354 S.E.2d 420, 421 (Ga. 1987). Consequently, the plaintiffs’ appeal was timely filed; the trial court erred in ruling otherwise and dismissing the appeal.
Reversed and remanded.
BRODERICK, J., did not sit; BATCHELDER, J., retired, sat by special assignment under RSA 490:3; HORTON, J., with whom THAYER, J., joined, dissented; the others concurred.