Legal Holidays are (RCW 1.16.050):
Sundays
New Year's Day
Martin Luther King Birth Day
President's Day
Memorial Day
Juneteenth Day
Independence Day
Labor Day
Veteran's Day
Thanksgiving Day
Thanksgiving Friday
Christmas Day
Courts of Record (Appellate and Superior) are closed on legal holidays (2.28.100)
County Clerks' Offices must remain open on all judicial days - every day except Saturdays, Sundays, and legal holidays (CR78; AGO 63-64 No. 93)
District Courts are open except on non-judicial days (legal holidays) (3.30.040)
Municipal Courts are open as prescribed by the legislative body of the city, but are not open on non-judicial days (legal holidays) (3.50.110)