(1) Definitions.

(a) "Day" means calendar day whenever used in this chapter, unless otherwise specified.

(b) "Business day" as used in this chapter, means any day when the commission's offices are open to the public as provided in WAC 480-07-120.

(2) Computation of time. The period of time for doing an act governed by this chapter is determined by excluding the first day and including the last day, unless the last day is not a business day, in which circumstance the period runs until the end of the next business day.

(3) Variation from time limits. The commission may modify the time limits stated in chapter 34.05 RCW, subject to the requirements of RCW 34.05.080. The commission may modify the time limits stated in a commission rule, subject to other requirements of law. WAC 480-07-385 governs continuances or extensions of time in adjudicative proceedings.