(1) For the purposes of these rules, the term "day" means calendar day, unless otherwise specified.

(2) In computing any period of time for acts required by the board's rules, time will be computed by excluding the first day and including the last day unless the last day falls upon a Saturday, Sunday, or legal holiday. In that event, the period runs until the end of the next day which is not a Saturday, Sunday, or legal holiday.

(3) The date of service is computed from the date on which service is made, as shown by the certificate of service or date of mailing. Service made by mail is complete upon mailing.

(4) Except as to dates fixed by statute and not subject to modification, the board may enlarge the time to perform an act required by these rules upon a written request of a party and good cause shown. A written request for an enlargement of time shall indicate that every other party has been contacted and whether any other party objects to the request.