In computing any period of time, the date of the act or event from which the designated period of time begins to run shall not be included. The last day of the time period must be included, unless it is a Saturday, a Sunday, or a legal holiday. When a period of time prescribed or allowed is less than seven days, intermediate Saturdays, Sundays, and legal holidays must be excluded in the computation. As used in this code, “legal holiday” includes holidays as listed in the Cowlitz Indian Tribe’s Paid Holiday Schedule for the current fiscal year.