In computing a period of days for the purposes of this chapter, unless otherwise provided by statute, the period begins on the day after the act, event, or default in question and ends at the end of the last day of that designated period, unless that day is a Saturday, Sunday, or legal holiday on which the office of the executive director is closed, in which event the period ends at the end of the next day that is not a Saturday, Sunday, or legal holiday. All time periods and deadlines are expressed in calendar days, unless expressly provided otherwise.