(a) Computation. In computing any period of time prescribed or allowed by these rules, by order of court, or by any applicable statute or rule, the day of the act, event, or default after which the designated 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, a Sunday, or a legal holiday, in which event the period runs until the end of the next day which is not a Saturday, a Sunday, or a legal holiday. When the period of time prescribed or allowed is less than seven days, intermediate Saturdays, Sundays, and legal holidays shall be excluded in the computation. As used in this rule, “legal holiday” includes any day appointed as a holiday by the President or the Congress of the United States or so designated by the laws of the Commonwealth.(b) Enlargement. When by these rules or by a notice given thereunder or by order or rule of court an act is required or allowed to be done at or within a specified time, the court for cause shown may at any time in its discretion (1) with or without motion or notice order the period enlarged if a request therefor is made before the expiration of the period originally prescribed or as extended by a previous order; or (2) upon motion made after the expiration of the specified period to permit the act to be done where the failure to act was the result of excusable neglect; or (3) permit the act to be done by stipulation of the parties; but the court may not extend the time for taking any action under rules 25 and 29 except to the extent and under the conditions stated therein.(c) For Motions, Affidavits in Superior Court. A written motion, other than one which may be heard ex parte, and notice of the hearing thereof shall be served on all interested parties not later than seven days prior to the hearing unless a different period is fixed by these rules or by order of the court. For cause shown, such an order may issue upon an ex parte application. When a motion is supported by affidavit, the affidavit shall be served with the motion. Opposing affidavits shall be served not later than one day before the hearing, unless the court permits them to be served at a later time.