(a) Computation of Time. In computing any period of time prescribed by these rules, by order of court, or by any applicable statute, 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 shall be included, unless it is a Saturday, Sunday or a legal holiday, in which event the period shall extend until the end of the next day which is not a Saturday, Sunday or a legal holiday. When the period of time prescribed or allowed is less than 7 days, intermediate Saturdays, Sundays and legal holidays shall be excluded in the computation. As used in this rule "legal holiday" means those days specified in G.L. c. 4, § 7 and any other 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 of Time. The appellate court or a single justice for good cause shown may upon motion enlarge the time prescribed by these rules or by its order for doing any act, or may permit an act to be done after the expiration of such time; but neither the appellate court nor a single justice may enlarge the time for filing a notice of appeal beyond one year from the date of entry of the judgment or order sought to be reviewed, or, in a criminal case, from the date of the verdict or finding of guilt or the date of imposition of sentence, whichever date is later.

(c) Additional Time After Service by Mail. Whenever a party is required or permitted to do an act within a prescribed period after service of a paper upon him and the paper is served by mail, 3 days shall be added to the prescribed period.

Amended May 15, 1979, effective July 1, 1979.