925 area code: location, time zone and current time in the East Bay

Key points about the 925 area code

• The 925 area code serves the East Bay and Tri-Valley.
• It uses Pacific Time (UTC-8 standard, UTC-7 in summer).
• 925 was split from 510 in 1998.
• It covers Contra Costa and eastern Alameda counties.
• Concord and Walnut Creek are among its largest cities.

925 area code at a glance

Where is the 925 area code?

The 925 area code is located in East Bay, California, United States. The 925 area code covers the eastern San Francisco Bay Area, including Contra Costa County and the Tri-Valley in California, United States. It uses the Pacific Time Zone and was split from the 510 code in 1998.

The East Bay is one of several California metros in this guide. See the related California codes for 916 area code (Sacramento), 669 area code (San Jose), 559 area code (Fresno).

What time zone is the 925 area code in?

The 925 area code follows Pacific Time (PT). In practice that means UTC-8 (PST) and UTC-7 during daylight saving (PDT).

History of the 925 area code

The 925 area code was created in 1998 when it was split from the 510 code that covers the inner East Bay. The new code took on Contra Costa County and the eastern part of Alameda County, an area that was growing quickly at the time. It has served the same suburban East Bay region ever since.

Nearby area codes

Cities covered by the 925 area code

Largest telephone carriers

The main networks providing service across the 925 area code include:

• AT&T
• Verizon
• T-Mobile
• Comcast (Xfinity Mobile)

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