est là gì

From Wikipedia, the không lấy phí encyclopedia

Bạn đang xem: est là gì

This article is about time zone in the Americas. For the time zone in nước Australia, see Australian Eastern Time.

Eastern Time Zone
Time zone

  Eastern Time Zone

UTC offset
Current time
18:54, 27 August 2023 EST [refresh]
19:54, 27 August 2023 EDT [refresh]
Observance of DST
DST is observed in parts of this time zone.

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, and the state of Quintana Roo in Mexico.

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 lớn 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 lớn 1:00 a.m. EST, which results in one hour being duplicated. Southern parts of the zone in Panama and the Caribbean, however, tự not observe daylight saving time.


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. The easternmost and northernmost counties in Kentucky were added to lớn 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 lớn Eastern Time.[1] 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).[2] 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.[3]

Daylight saving time[edit]

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 rẩy from the last Sunday of April until the last Sunday in October.[4] The act was amended to lớn make the first Sunday in April the beginning of daylight saving time beginning in 1987.[4]

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 lớn 3:00 a.m. EDT on the second Sunday in March, and return from 2:00 a.m. EDT to lớn 1:00 a.m. EST on the first Sunday in November.[4]

In Canada, daylight saving time begins and ends on the same days and at the same times as it does in the United States.[5][6]


Xem thêm: hồ sơ xin việc cần những gì

In Canada, the following provinces and territories are part of the Eastern Time Zone:[7] 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,[8] and several other very localized areas. None of those areas are in the Eastern Time Zone.

United States[edit]

The boundary between time zones is mix 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.[9]

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

Five states are divided between the Eastern Time Zone and the Central Time Zone. The following locations observe Eastern Time:

  • Florida: Big Bend regions east of the Apalachicola River and portions of Gulf County south of the Intracoastal Waterway
  • Indiana: The entire state except for northwest Gary area and southwest Evansville area
  • Kentucky: The eastern portion of the state, including its three largest metropolitan areas: Louisville, Lexington, and Northern Kentucky
  • Michigan: The entire state except for the four Upper Peninsula counties that border Wisconsin: Gogebic, Iron, Dickinson, and Menominee
  • Tennessee: All of East Tennessee, except for Bledsoe, Cumberland, and Marion counties[10]

Additionally, Phenix City, Alabama, and several nearby communities in Russell County, Alabama, unofficially observe Eastern Time.[11] This is due to lớn their close proximity to lớn Columbus, Georgia, which is on Eastern Time.


  • Quintana Roo: This is the only Mexican state to lớn observe EST. It moved from Central Time to lớn Eastern Time after a successful lobbying effort by tourism interests.[12] Quintana Roo does not observe daylight saving time.

Caribbean islands[edit]

The Bahamas and Haiti officially observe both Eastern Standard Time during the winter months and Eastern Daylight Time during the summer months. Cuba generally follows the U.S. with Eastern Standard Time in the winter, and Eastern Daylight Time in the summer, but the exact day of change varies year to lớn year. The Cayman Islands and Jamaica use Eastern Standard Time year-round.[citation needed]

Turks and Caicos Islands[edit]

The Turks and Caicos Islands followed Eastern Time with daylight saving until năm ngoái, when the territory switched to lớn the Atlantic Time Zone. The Turks and Caicos Islands switched back to lớn the pre-2015 schedule in March 2018.[13] A 2017 consultation paper highlighted the advantage for business and tourism of being in the same time zone as the eastern United States as an important factor in the decision.[14]

South America[edit]

In South America, the Brazilian states of Acre and the southwest part of Amazonas use Eastern Standard Time.[15] In 2008, Brazil changed the zone of these regions to lớn be closer to lớn that of the Brazilian Capital; however, the change was unpopular and thus undone in 2013.[16] Additionally, the countries of Panama, Colombia, Peru, and Ecuador (excluding the Galápagos Islands, which use Central Standard Time), also use Eastern Standard Time year-round.[17]

Xem thêm: đường cao tam giác vuông

See also[edit]

  • Effects of time zones on North American broadcasting


  1. ^ "Why Louisville?". Louisville magazine. Archived from the original on July đôi mươi, 2018. Retrieved February 10, 2018.
  2. ^ Klas, Mary Ellen (March 6, 2018). "Legislature approves year-round daylight saving time—but it's not a done khuyễn mãi giảm giá yet". Miami Herald. Retrieved March 30, 2018.
  3. ^ Patton, Jessica (October 7, 2020). "Ontario MPP puts forward bill to lớn make Daylight Saving Time standard time". Global News. Retrieved October 9, 2020.
  4. ^ a b c Prerau, David (2006). "Early adoption and U.S. Law". Daylight Saving Time. Web Exhibit. Retrieved April 23, 2007.
  5. ^ Law, Gwillim (September 21, 2007). "United States Time Zones".
  6. ^ "Daylight Saving Time Starts Sunday". Government of Ontario. March 7, 2008. Retrieved September 21, 2010.
  7. ^ "Time zones and daylight saving time". National Research Council Canada. March 23, 2019. Retrieved March 7, 2020.
  8. ^ "Yukon to lớn over seasonal time change". March 4, 2020. Retrieved May 13, 2022.
  9. ^ The specification for the Eastern Time Zone is mix forth at 49 C.F.R. § 71.4, and is listed in text Archived January 13, 2012, at the Wayback Machine and PDF Archived January 14, 2012, at the Wayback Machine formats. The boundary between Eastern and Central is mix forth at 49 C.F.R. § 71.5, and is listed in text and PDF Archived January 13, 2012, at the Wayback Machine formats.
  10. ^ "Parts of Eastern Alabama split between 2 time zones". Archived from the original on March 10, 2016. Retrieved March 22, 2009.
  11. ^ Emily. "Our Community". Phenix City, Alabama. Retrieved January 10, 2022.
  12. ^ "On Mexican Time: Changing Time Zones To Accommodate Tourism". Forbes. Retrieved January 29, 2015.
  13. ^ "DST Dates Confirmed". July 25, 2017. Retrieved January 10, 2019.
  14. ^ "Consultation paper Daylight Saving" (PDF). April 2017. pp. 6–7. Archived from the original (PDF) on January 10, 2019. Retrieved January 10, 2019.
  15. ^ Every, Decree. "Brazil Time Zones". Retrieved May 1, 2021.
  16. ^ President, Brazil'S. "Brazil: Acre and parts of Amazonas switch time zones". Retrieved May 1, 2021.
  17. ^ "South America Time Zones". Worldatlas. Retrieved May 1, 2021.

External links[edit]

  • Official U.S. time in the Eastern time zone (archived April 24, 2007)
  • North American Time Zone border data and images
  • World time zone map Archived December 24, năm ngoái, at the Wayback Machine
  • U.S. time zone map Archived February 15, 2009, at the Wayback Machine
  • History of U.S. time zones and UTC conversion Archived August 8, 2011, at the Wayback Machine
  • Canada time zone map
  • Time zones for major world cities
  • Official times across Canada
  • Federal Regulations defining time zones (archived May 28, 2010)