Located in the Pacific (GMT -08:00) time zone. Area code 408 serves the state of California. This area code was assigned on January 1st, 1959. On January 1st, 1959 it went into service. 408 is a General Purpose Code. 408 service area does overlap with 669 area codes. Dialing pattern for local calls within the same NPA (area code) is 1+10D.