In this appeal from the May 20, 1999 decision of the Labor and Industrial Relations Appeals Board (the Board), the sole issue is whether the Board properly dismissed as untimely the appeal of Claimant-Appellant (Claimant) from the March 23, 1999 decision of the Director of Labor and Industrial Relations (the Director) determining Claimant's entitlement to further workers' compensation medical benefits. The applicable statute is Hawaii Revised Statutes (HRS) 386-87 (1993), which provides, in relevant part, as follows: Appeals to appellate board. (a) a decision of the Director shall be final and conclusive between the parties, except as provided in section 386-89, unless within twenty days after a copy has been sent to each party, either party appeals therefrom to the Board by filing a written notice of appeal with the Board or the department (of labor and industrial relations). In all cases of appeal filed with the department the Board shall be notified of the pendency thereof by the Director. . . . The Director's decision contained in the record on appeal is time-stamped March 23, 1999, at 8:03 a.m. Included in the record is a Department of Labor and Industrial Relations (DLIR) Disability Compensation Division form (WC-9a), entitled "Record of Decision Distribution," that includes a line for recording the date that the Director's decision was mailed to Claimant. However, although the form is time-stamped March 23, 1999, at 8:03 a.m., the date the Director's decision was mailed or "sent to" Claimant is not typed or written in the space provided. Additionally, the record includes no postmarked envelope or certificate by a DLIR or postal service employee, indicating the date of mailing. See Waikiki Marketplace Inv. Co. v. Chair of the Zoning Board of Appeals of the City and County of Honolulu, 86 Haw. 343, 349-50, 949 P.2d 183, 189-90 (App. 1997). In light of the absence of evidence in the record as to exactly when the Director's decision was mailed or sent to Claimant, we are unable to evaluate whether Claimant's appeal of the Director's decision to the Board was untimely. Accordingly, we vacate the Board's May 20, 1999 decision and remand for further proceedings.