Garden Grove, CA utilizes an area code overlay in which area codes 657 and 714 serve the same geographic area. The area code overlay which is in use today was established in 1999 at which time area code 657 was created as an overlay of area code 714. Area code 714 was created from a split of area code 213 and put into service in 1951. Ten digit dialing (area code + seven digit number) is necessary because two different homes in the same geographic area can have the same seven digit phone number but each would have a different area code.
In addition to Garden Grove, CA area codes 657 and 714 serves a portion of Los Angeles County, much of northern Orange County and the Chino Hills area in southwestern San Bernardino County including the larger communities of Anaheim, Atwood, Brea, Buena Park, Cypress, Fountain Valley, Fullerton, Garden Grove, Holiday, Huntington Beach, Irvine, Newport Beach, Orange, Placentia, Santa Ana, Silverado, Stanton, Tustin, Westminster, and Yorba Linda in addition to many smaller communities within the service area.
Garden Grove, CA is located in Orange County and observes the Pacific Time Zone.