Area code 804 is an essential telephone area code within the North American Numbering Plan, specifically serving east-central Virginia. Here are some important details about this area code:

Geographic Coverage and Major Cities: Area code 804 covers the east-central portion of Virginia, including Richmond and most of its metropolitan area. It encompasses several significant cities and towns such as Chesterfield, Henrico, Hopewell, Mechanicsville, Powhatan, Midlothian, Petersburg, and Colonial Heights. This coverage makes it an integral part of the telecommunication infrastructure in this region of Virginia​​.

Time Zone: The area code is located in the Eastern Time Zone. Like most areas in the Eastern United States, it observes Daylight Saving Time, which involves adjusting the clocks forward in spring and backward in autumn to extend evening daylight during the warmer months of the year​​.

Long-standing Service and Coverage: Area code 804 has been in service since 1973 and encompasses 89 cities and 31 counties in Virginia. This includes counties such as Richmond City County, Chesterfield County, Henrico County, Hanover County, and Prince George County. The area code's long history and extensive coverage of cities and counties underscore its importance in Virginia's communication network​​​​.

In summary, area code 804 plays a crucial role in the telecommunications of east-central Virginia, particularly around Richmond and its metropolitan area. Its establishment in 1973, extensive coverage of numerous cities and counties, and location in the Eastern Time Zone are significant aspects of its operation in the state's communication infrastructure.