Upon the day specified in the notice of the meeting of the board of equalization, the board of directors which is hereby constituted a board of equalization for that purpose, shall meet and continue in session from day to day as long as may be necessary, not to exceed ten days exclusive of Sundays, to hear and determine such objections to the valuation and assessment as may come before them and the board may change the valuation as may be just.
RCW 89.30.601