The assessment list shall be completed on or before July 15, and, on the first Tuesday of August in each year and from day to day thereafter, Sundays excepted, the board of directors shall sit to hear complaints and to correct errors in said assessment until all complaints filed with the secretary or presented to the board have had an opportunity to be heard and determined. The classification of any lands on the graduated scale shall not be changed or determined at said hearings.
C.R.S. § 37-23-108