RCW 84.08.190

For the purpose of instruction on the subject of taxation, the county assessors of the state shall meet with the department of revenue at the capital of the state, or at such place within the state as they may determine at their previous meeting, on the second Monday of October of each year or on such other date as may be fixed by the department of revenue. Each assessor shall be paid by the county of his or her residence his or her actual expenses in attending such meeting, upon presentation to the county auditor of proper vouchers.