Located in the Pacific (GMT -08:00) time zone. Area code 564 serves the state of Washington. This area code was assigned on September 20th, 1999. On August 28th, 2017 it went into service. 564 is a General Purpose Code. 564 service area does overlap with 360 area codes. Dialing pattern for local calls within the same NPA (area code) is 10D.