The computation of any time period of 11 days or less shall be by the working days of the pueblo or tribal court from which the appeal is taken. The computation of any time period over 11 days shall be by calendar days, provided that, if the last day of any period falls on a weekend, holiday, or other non-working day of the pueblo or tribal court from which the appeal is taken, the last day shall be extended to the next working day of the lower tribal court.