(a) Computation. In computing any time period under these rules, 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. Intermediate Saturdays, Sundays, and legal holidays shall be included. Whenever an act required to be performed under these rules may be accomplished by mail, the act shall be deemed to have been performed on the date of the postmark on the mailed article.(b) Enlarged. For good cause, when permitted by statute or these rules, the court may enlarge any time period.