The entire state of California is located within the Pacific time zone. As of 2014, the state observes Pacific Standard Time between the middle of the fall and the end of the winter. At all other times, Pacific Daylight Time is observed.
The Pacific time zone is one of four principal time zones observed in the continental United States. Along with California, the zone includes the entire state of Washington and large portions of Oregon, Nevada and Idaho. Moving from west to east, the other time zones in the continental United States include Mountain, Central and Eastern. Alaska and Hawaii observe the final two time zones in the United States, Alaskan time and Hawaii-Aleutian time.