Wash. Const. art. II, § 12

(1) Regular Sessions. A regular session of the legislature shall be convened each year. Regular sessions shall convene on such day and at such time as the legislature shall determine by statute. During each odd-numbered year, the regular session shall not be more than one hundred five consecutive days. During each even-numbered year, the regular session shall not be more than sixty consecutive days.

(2) Special Legislative Sessions. Special legislative sessions may be convened for a period of not more than thirty consecutive days by proclamation of the governor pursuant to Article III, section 7 of this Constitution. Special legislative sessions may also be convened for a period of not more than thirty consecutive days by resolution of the legislature upon the affirmative vote in each house of two-thirds of the members elected or appointed thereto, which vote may be taken and resolution executed either while the legislature is in session or during any interim between sessions in accordance with such procedures as the legislature may provide by law or resolution. The resolution convening the legislature shall specify a purpose or purposes for the convening of a special session, and any special session convened by the resolution shall consider only measures germane to the purpose or purposes expressed in the resolution, unless by resolution adopted during the session upon the affirmative vote in each house of two-thirds of the members elected or appointed thereto, an additional purpose or purposes are expressed. The specification of purpose by the governor pursuant to Article III, section 7 of this Constitution shall be considered by the legislature but shall not be mandatory.

(3) Committees of the Legislature. Standing and special committees of the legislature shall meet and conduct official business pursuant to such rules as the legislature may adopt.