Haw. Rev. Stat. § 291D-11: Time computation.

In computing any period of time prescribed or allowed by this chapter, the day of the act, event, or default from which the period of time begins to run shall not be included. The last day of the period so computed shall be included, unless it is a Saturday, Sunday, or legal holiday in which event the period runs until the end of the next day that is not a Saturday, Sunday, or legal holiday. Intermediate Saturdays, Sundays, and legal holidays shall be included. Whenever an act required to be performed under this chapter may be accomplished by mail, the act shall be deemed to have been performed on the date of the postmark on the mailed article.