In computing any period of time prescribed or allowed 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 is not to be included. The last day of the period so computed is to be included, unless it is a Saturday, Sunday or a State or Federal holiday, in which event the period runs until the end of the next day which is neither a Saturday, Sunday nor such holiday. When the period of time prescribed or allowed is less than seven days, intermediate Saturdays, Sundays and holidays shall be excluded in the computation. A half holiday shall be considered as other days and not as a holiday.