In computing any period of time prescribed or allowed by these rules, by order of court, or by applicable law, 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, Sunday, or a legal holiday, in which event the period shall extend until the end of the next day that is not a Saturday, Sunday, or a legal holiday as specified in RSA ch. 288, as amended.