On or before the second Monday in July of each year, the county auditor or chief financial officer designated in a charter county shall notify in writing each county official, elective or appointive, in charge of an office, department, service, or institution of the county, to file with him or her on or before the second Monday in August thereafter detailed and itemized estimates, both of the probable revenues from sources other than taxation, and of all expenditures required by such office, department, service, or institution for the ensuing fiscal year.
RCW 36.40.010