Whenever a person or agency has a right or is required to take action within the period prescribed or allowed by this chapter for an agency appeal, the presiding officer may (1) before the expiration of the prescribed period, with or without notice, extend such period; or (2) upon motion, permit the act to be done after the expiration of a specified period where the failure to act is reasonably shown to be excusable.
Haw. Code R. § 18-231-91-22