Eastern Time Zone
(furthest right yellow)
UTC offset
EST	UTC−5:00
EDT	UTC−4:00
Observance of DST
DST is observed throughout this time zone between the 2nd Sunday in March and the 1st Sunday in November.
DST began	Mar 10, 2013
DST ends	Nov 3, 2013

The Eastern Time Zone (ET) encompasses 17 U.S. states in the eastern part of the contiguous United States, parts of Canada and three countries in South America.

Places that use Eastern Standard Time (EST) when observing standard time (autumn/winter) are 5 hours behind Coordinated Universal Time (UTC−05:00).

Eastern Daylight Time (EDT), when observing daylight saving time (spring/summer) is 4 hours behind Coordinated Universal Time (UTC−04:00).

In the northern parts of the time zone, during 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." During 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.

History [edit]

The Uniform Time Act instituted EDT as the last Sunday of April in the United States which started in 1966.^[1] EST would be observed again on the last Sunday in October. The act was amended to make the first Sunday in April the beginning of EDT as of 1987.^[1] The Energy Policy Act of 2005 extended daylight saving time in the United States beginning in 2007. So local times change at 2:00 a.m. EST to 3:00 a.m. EDT on the second Sunday in March and return at 2:00 a.m. EDT to 1:00 a.m. EST on the first Sunday in November.^[1] In Canada, the time changes as it does in the United States.^[2][3]

Canada [edit]

In Canada, the following provinces and territories are part of the Eastern Time Zone:

• Ontario (excluding areas west of Thunder Bay but including Atikokan)
• Quebec (excluding far eastern Côte-Nord and the Magdalen Islands)
• East-central Nunavut (including part of Melville Peninsula and most of Ellesmere and Baffin Islands, including Iqaluit; Southampton Island does not observe DST)

United States [edit]

The location of time zones has to dividing lines between theirs to set forth in the Code of Federal Regulations at 49 CFR 71.^[4]

The District of Columbia and seventeen states are located entirely within the Eastern Time zone:

Six states are split between Eastern and Central time:

• Alabama: The entire state is officially in the Central Time Zone. However, a handful of communities unofficially observe Eastern Time because they are part of the Columbus, Georgia metropolitan area – Phenix City, Smiths Station, Lanett, and Valley.^[5]
• Florida: All of Florida is in the Eastern Time zone except for the portion of the Florida Panhandle west of the Apalachicola River. As the Eastern–Central zone boundary approaches the Gulf of Mexico, it follows the Bay/Gulf county line.
• Indiana: All of Indiana observes Eastern Time except for six northwestern counties in the Chicago metropolitan area and six southern counties in the Evansville metropolitan area.
  • Until 2006, the portions of Indiana within the Eastern Time Zone observed Eastern Standard Time year-round – except that five counties near Cincinnati and Louisville customarily observed Eastern Daylight Time despite legally being on Eastern Standard Time. See Time in Indiana.
• Kentucky: Roughly, the eastern half of the state, including all of metropolitan Louisville is in the Eastern Time Zone and the western half is in the Central Time Zone; however, the boundary is not a neat north–south line but runs northwest–southeast.
• Michigan: All of Michigan observes Eastern Time except the four counties in the Upper Peninsula along the border with Wisconsin, which observe Central Time – Gogebic, Iron, Dickinson, Menominee. Historically the entire state observed Central Time. When daylight saving time was first introduced, the Lower Peninsula remained on DST after it formally ended, effectively re-aligning itself into the Eastern Time Zone. The Upper Peninsula continued to observe Central Time until 1972, when all but the four counties noted changed to Eastern Time.
• Tennessee: Most of the eastern third of Tennessee is legally on Eastern Time. The area is roughly but not entirely coextensive with the region formally known as "East Tennessee". Specifically, three East Tennessee counties--Bledsoe, Cumberland, and Marion--are on Central Time.

Eastern Time is also used somewhat as a de facto official time for all of the United States, since it includes the capital (Washington, D.C.), the largest city (New York City), and approximately half the country's population.^{[citation needed]} National media organizations will often report when events happened or are scheduled to happen in Eastern Time even if they occurred in another time zone, and TV schedules are also almost always posted in Eastern Time. Major professional sports leagues also post all game times in Eastern time, even if both teams are from the same time zone, outside of Eastern Time. For example a game time between two teams from Pacific Time Zone will still be posted in Eastern time (for example, one may see "Seattle at Los Angeles" with "10:00 p.m." posted as the start time for the game, often without even clarifying the time is posted in Eastern time).^{[citation needed]}

Most cable television and national broadcast networks advertise airing times in Eastern time. National broadcast networks (ABC, CBS, The CW, Fox Network, NBC) generally have two primary feeds, an eastern feed for Eastern and Central time zones, and a western feed for the Pacific Time Zone. The prime time is set on Eastern and Pacific at 8:00 p.m., with the Central time zone stations receiving the eastern feed at 7:00 p.m. local time. Mountain Time Zone stations receive a separate feed at 7:00 p.m. local time. As Arizona does not observe daylight saving time, during the summer months, it has its own feed at 7:00 p.m. local time. Cable channels with a separate western feed (such as HBO, whose western feed is called "HBOW") generally air the same programming as the eastern feed delayed by three hours. Other cable networks such as the Discovery family of networks repeat their prime time programming three hours later; this allows for the same show to be advertised as airing at "8:00 p.m. E/P" (that is, "8:00 p.m. Eastern and Pacific time"). Networks specializing in the airing of sports events, such as ESPN, advertise all of their programming in Eastern and Pacific, incorporating the 3-hour time difference (as in "8:00 p.m. Eastern/5:00 p.m. Pacific") and leaving viewers in the remaining time zones to calculate start time in their own areas.^{[citation needed]}

Mexico [edit]

• Quintana Roo: this eastern state followed EST for an almost-17-year period (1982 to some time in 1998).^[6]

As of in Mexico, the time zone is different in comparison to the eastern hemisphere of only the United States by hours.

Central American and the Caribbean [edit]

Jamaica, Haiti, and the Cayman Islands in the Caribbean, and Panama in Central America use Eastern Standard Time UTC−05 year round. Cuba is usually the same as Eastern Standard Time in the winter, and Eastern Daylight Time in the summer, but often changes on different days.

See also [edit]

• Effects of time zones on North American broadcasting
• Time in Colombia
• Time in Indiana
• Time in Brazil
• Time in France

References [edit]

External links [edit]

• Official U.S. time in the Eastern time zone
• North American Time Zone border data and images
• World time zone map
• U.S. time zone map
• History of U.S. time zones and UTC conversion
• Canada time zone map
• Time zones for major world cities
• Official times across Canada
• Federal Regulations defining time zones