Eastern Standard Time (North America)

The Eastern Time Zone (ET) is a time zone encompassing part or all of 23 states in the eastern part of the United States, parts of eastern Canada, the state of Quintana Roo in Mexico, Panama, Colombia, mainland Ecuador, Peru, and a small portion of westernmost Brazil in South America, along with certain Caribbean and Atlantic islands.

Places that use:

* Eastern Standard Time (EST), when observing standard time (autumn/winter), are five hours behind Coordinated Universal Time ( UTC−05:00).
* Eastern Daylight Time (EDT), when observing daylight saving time (spring/summer), are four hours behind Coordinated Universal Time ( UTC−04:00).
On the second Sunday in March, at 2:00 a.m. EST, clocks are advanced to 3:00 a.m. EDT leaving a one-hour "gap". On the first Sunday in November, at 2:00 a.m. EDT, clocks are moved back to 1:00 a.m. EST, thus "duplicating" one hour. Southern parts of the zone (Panama and the Caribbean) do not observe daylight saving time.

History

The boundaries of the Eastern Time Zone have moved westward since the Interstate Commerce Commission (ICC) took over time-zone management from railroads in 1938. For example, the easternmost and northernmost counties in Kentucky were added to the zone in the 1940s, and in 1961 most of the state went Eastern. In 2000, Wayne County, on the Tennessee border, switched from Central to Eastern. Within the United States, the Eastern Time Zone is the most populous region, with nearly half of the country's population.

In March 2019, the Florida Legislature passed a bill requesting authorization from Congress for year-round daylight saving time, which would effectively put Florida on Atlantic Standard Time year-round (except for west of the Apalachicola River, which would be on Eastern Standard Time year-round). A similar bill was proposed for the Canadian province of Ontario by its legislative assembly in late 2020, which would have a similar effect on the province if passed.

Daylight saving time

For those in the United States, daylight saving time for the Eastern Time Zone was introduced by the Uniform Time Act of 1966, which specified that daylight saving time would run from the last Sunday of April until the last Sunday in October. The act was amended to make the first Sunday in April the beginning of daylight saving time beginning in 1987.

Later, the Energy Policy Act of 2005 extended daylight saving time in the United States, beginning in 2007. Since then, local times change at 2:00 a.m. EST to 3:00 a.m. EDT on the second Sunday in March, and return from 2:00 a.m. EDT to 1:00 a.m. EST on the first Sunday in November.

In Canada, daylight saving time begins and ends on the same days and at the same times as it does in the United States.

Canada

In Canada, the following provinces and territories are part of the Eastern Time Zone: Within Canada, as with the United States, the Eastern Time zone is the most populous time zone.
* Most of Ontario
* Most of Quebec
* Most of Nunavut

Most of Canada observes daylight saving time synchronously with the United States, with the exception of Saskatchewan, Yukon, and several other very localized areas.

United States

The boundary between time zones is set forth in the Code of Federal Regulations, with the boundary between the Eastern and Central Time Zones being specifically detailed in 49 C.F.R. part 71.

Washington, D.C. and 17 states are located entirely within the Eastern Time Zone. They are:

* Connecticut
* Delaware
* Georgia
* Maine
* Maryland
* Massachusetts
* New Hampshire