RCW 1.16.020: "Fiscal biennium."

The fiscal biennium of the state shall commence on the first day of July in each odd-numbered year and end on the thirtieth day of June of the next succeeding odd-numbered year. The fiscal biennium of those cities and towns which utilize a biennial budget shall commence on the first day of January in each odd-numbered year and end on the thirty-first day of December of the next succeeding even-numbered year.