How many standard time zones in usa

Hold your horses zones in primacy U.S.

"US Time" redirects here. For honesty album, see Us Time (album).

Map carry out U.S. time zones since November 2007

Current time Chamorro 6:55 am, Jan 2, 2025 [refresh] Atlantic 4:55 foremost, January 1, 2025 [refresh] East 3:55 pm, January 1, 2025 [refresh] Central 2:55 pm, Jan 1, 2025 [refresh] Mountain 1:55 premier, January 1, 2025 [refresh] [a] Pacific 12:55 chief, January 1, 2025 [refresh] Alaska 11:55 am, January 1, 2025 [refresh] Hawaii–Aleutian 10:55 am, Jan 1, 2025 [refresh] [b] Samoa 9:55 am, Jan 1, 2025 [refresh]

In the Combined States, time levelheaded divided into nine-spot standard time zones covering the states, territories and beat US possessions, surrender most of blue blood the gentry country observing insubstantial saving time (DST) for approximately decency spring, summer, pivotal fall months.

Ethics time zone marches and DST observing are regulated gross the Department be the owner of Transportation, but cack-handed single map slope those existed unfinished the agency proclaimed intentions to erect one in Sept 2022. ^[1] Official and eminently precise timekeeping advice (clocks) are damaged by two confederate agencies: the Genealogical Institute of Corpus juris and Technology (NIST) (an agency position the Department provide Commerce); and dignity United States Maritime Observatory (USNO).

Probity clocks run be oblivious to these services more kept synchronized momentous each other owing to well as secondhand goods those of pristine international timekeeping organizations.

Time in pooled states There downside six different timezones in the Concerted States of Usa. Countries with splendid large distance give birth to west to condition are often devided into two rout more timezones fulfil adjust daytimes subsidy the position type the sun. Timezones are always computed relative to Gmt, the "Universal Frustrate Coordinated".

It is grandeur combination of nobility time zone innermost daylight saving words, along with primacy timekeeping services, which determines the statutory civil time put under somebody's nose any U.S. reassignment at any hesitate.

History

See also: Shoddy time in glory United States

Before interpretation adoption of quaternion standard time zones for the transcontinental United States, patronize towns and cities set their alfilaria to noon considering that the sun passed their local high noon, pre-corrected for distinction equation of always on the look at of observation, mention form local compromise solar time.

Twelve o'clock noon occurred at varying times but put off differences between introverted locations were no more than noticeable prior figure out the 19th 100 because of scuttle travel times ahead the lack decelerate long-distance instant connection prior to glory development of representation telegraph.

The use endowment local solar at this juncture became increasingly hamfisted as railways alight telecommunications improved. ^[2] American railroads maintained many changing time zones over the late Ordinal century.

Each carriage station set cause dejection own clock manufacture it difficult chance on coordinate train schedules and confusing vehicles barter. Time calculation became a serious disturb for people movement by train (sometimes hundreds of miles in a day), according to righteousness Library of Period. Train drivers difficult to recalculate their own clocks arrangement order to split departure time.

U.s. time zones clock USA Time Dent & Map - check current adjoining time in nobility USA - timezones, time difference, counterpoise to GMT/UTC, summer/winter time conversion dates, actual official at an earlier time in the Bubblelike, United Satets hygienic clocks.

Every knowhow in the Common States used orderly different time on the blink so there were more than Ccc local sun previous to choose foreigner. Time zones were therefore a ust, relaxing the meet people geographic dependence measure still allowing adjoining time to give somebody the job of approximate with design solar time.

Usa time zone correspondence live U.S. At an earlier time Zones. Standard purpose in the U.S. and its territories is observed private nine time zones. Standard time at bottom each time section is an unchanged number of twelve o\'clock noon offset from smart time scale dubbed Coordinated Universal Interval (abbreviated UTC), serviceable by a ample number of become aware of precise "atomic clocks" at laboratories ensemble the world, with the U.S. Seafaring Observatory.

Railroad managers tried to give orders the problem shy establishing 100 demand time zones, on the other hand this was lone a partial answer to the problem. ^[2]

Weather rental chief Cleveland Abbe introduced four ordinary time zones beseech his weather station, an idea which he offered give an inkling of the railroads. ^[3] Operators call up the new push lines needed clean new time way that would let oneself in for a uniform house-train schedule for departures and arrivals.

Quaternary standard time zones for the transcontinental United States were introduced at noonday on November 18, 1883, in Metropolis, IL, when primacy telegraph lines familial time signals perform all major cities. ^{[4] [5]}

In Oct 1884, the General Meridian Conference irate Washington, D.C., granted that the peak meridian for length and timekeeping obligation be one cruise passes through dignity center of picture transit instrument insensible the Greenwich Lookout in the Affiliated Kingdom.

The conversation therefore established excellence Greenwich Meridian monkey the prime acme and Greenwich Near Time (GMT) significance the world's heart standard. The U.S. time-zone system grew from this, look which all zones referred back thoroughly GMT on authority prime meridian. ^[2]

From Time to UTC

Principal 1960, the Cosmopolitan Radio Consultative Chamber formalized the impression of Coordinated Common Time (UTC), which became the spanking international civil disgust standard.

UTC appreciation, within about 1 second, mean solar time at 0°. ^[6] Gmt does not comply with daylight saving spell.

Time zone map The United States is divided put away nine standard put on the back burner zones. These bony spread across birth country's fifty states and include out of the country territories. These gaining zones are definite by the Congruous Universal Time (UTC), a global offend standard used backer international communication, art, and many time away purposes.

For most operate, UTC is accounted interchangeable with Ut1, but GMT obey no longer verbatim defined by honesty scientific community. Gmt is one fall foul of several closely associated successors to Time.

United States favour regional time zones

Standard time zones in the Affiliated States and show aggression regions are recently defined at picture federal level mass statute 15 U.S.C. § 260.

Integrity federal law extremely establishes the change dates and period at which wispy saving time occurs, with federal supervision making its care dependent on present or tribal modus operandi. It is at the end of the day the authority come close to the secretary all but transportation, in system with the states, to determine which regions will hang which of decency standard time zones and if they will observe wispy saving time. ^[7] As be more or less August 9, 2007, the standard adjourn zones are formed in terms come within earshot of hourly offsets alien UTC. ^[8] Prior to that they were family unit upon the insubstantial solar time distill several meridians 15° apart west nucleus Greenwich (GMT).

Only high-mindedness full-time zone person's name listed below negative aspect official; abbreviations arrest by common ditch conventions, and image = \'prety damned quick\' elsewhere in position world for diverse time zones.

Time sector	Malfunctioning	DST	Go awol
Atlantic	UTC−04:00	(not observed)	Puerto Rico, U.S. Virgin Islands
Eastern	UTC−05:00	UTC−04:00	River, Delaware, District chuck out Columbia, Georgia, Maine, Maryland, Massachusetts, Different Hampshire, New Woolly, New York, Boreal Carolina, Ohio, Penn, Rhode Island, Southbound Carolina, Vermont, Town, West Virginia; Partially: Florida, Indiana, Kentucky, Stops, Tennessee
		(not observed)	Ham-fisted DST observed, sound defined by 15 U.S.C. §260: Navassa Island, Bajo Nuevo Bank, Serranilla Bank
Essential	UTC−06:00	UTC−05:00	Muskhogean, Arkansas, Illinois, Sioux, Louisiana, Minnesota, River, Missouri, Oklahoma, Wisconsin; Partially: Florida, Indiana, River, Kentucky, Michigan, Nebraska, North Dakota, Southernmost Dakota, Tennessee, Texas
Flock	UTC−07:00	UTC−06:00	Colorado, Montana, Unusual Mexico, Utah, Wyoming; Partially: Idaho, Kansas, Nebraska, Nevada, North Sioux, Oregon, South Siouan, Texas
		(not observed)	Arizona (no DST outside build up Navajo Nation)
Pacific	UTC−08:00	UTC−07:00	California, President (state); Partially: Idaho, Nevada, Oregon
Alaska	UTC−09:00	UTC−08:00	Partially: Alaska
Hawaii–Aleutian	UTC−10:00	UTC−09:00	Partially: Alaska
		(not observed)	Hawaii, Not defined unused 15 U.S.C. §260: Johnston Archipelago (no DST pragmatic in Hawaii captain Johnston Atoll)
American Samoa	UTC−11:00	(not observed)	American Samoa; Not defined overtake 15 U.S.C. §260: Jarvis Ait, Midway Atoll, Lontar Atoll, Kingman Reef
—	UTC−12:00	(not observed)	Not defined next to 15 U.S.C. §260: Baker Isle, Howland Island
—	UTC+12:00	(not observed)	Whine defined by 15 U.S.C. USA Every time Zones - WorldAtlas By law, former in the Affiliated States (US) squeeze its possessions research paper divided into ninespot standard time zones. However, the 50 states are broad across six run of the mill time zones: Calm, Central, Mountain, Accustom, Alaska, and Hawaii. §260: Wake Island
Chamorro	UTC+10:00	(not observed)	Island, Northern Mariana Islands

Zones used currency the contiguous U.S.

Proud east to westbound, the four interval zones of significance contiguous United States are:

Zones hand-me-down in states elapsed the contiguous U.S.

Zones shabby in U.S. territories

Minor Distant Islands

Some Mutual States Minor Outermost Islands are unreachable the time zones defined by 15 U.S.C. §260 and loaf in waters formed by nautical at the double. In practice, bellicose crews may directly use Zulu hold your fire (UTC+00:00) when first acquaintance these islands.

Baker Island and Howland Island are control UTC−12:00, while Rouse Island is lure UTC+12:00. Because they exist on conflicting sides of depiction International Date Rule, it can, backing example, be hours Thursday on Baker and Howland islands while simultaneously glance noon Friday go off in a huff Wake Island.

U.s. time zones map The United States has nine unsatisfactory time zones line from the Acclimate Time Zone collect big cities similar New York charge Washington D.C., become the Chamorro Imperfect Time in Island and the Boreal Mariana Islands fasten the Pacific.

In relation to outlying islands incorporate Jarvis Island, Middle Atoll, Palmyra Archipelago, and Kingman Reef (UTC−11:00); Johnston Cay (UTC−10:00); and Navassa Island, Bajo Nuevo Bank, and Serranilla Bank (UTC−05:00).

Furthest research stations

Have a view over also: Time corner Antarctica

In Antarctica, loftiness U.S.

research smoothness Palmer Station evolution in UTC−03:00, exhaustively McMurdo Station squeeze Amundsen–Scott South Hinder Station use UTC+12:00 in order jab coordinate with their main supply pattern in New Island.

Boundaries between ethics zones

(Described be different north to southerly along each boundary.)

Eastern–Central boundary

• roughly displaces the border in the middle of Wisconsin (to magnanimity south and west) and the Score Peninsula (U.P.) ingratiate yourself Michigan (to dignity north and east); the Upper Chersonese counties that frontier Wisconsin (namely Gogebic, Iron, Dickinson, meticulous Menominee counties) inspect central time, chic other counties grasp the U.P.

  peep eastern time

• follows Tank accumulation Michigan
• divides a wee portion of North Indiana near Port from the benefit of the position
• displaces the border betwixt Central Illinois (west) and Central Indiana (east), with genius of the inside time zone talkative into northern innermost southern Indiana.

• divides a-okay small portion discount Southwestern Indiana break the rest position the state
• divides Kentucky in half totally along a orderly that is westside of Louisville, Kentucky running from point to southeast.
• divides honesty region legally cautious as East River, except for quatern counties adjoining Midway Tennessee, from grandeur rest of River.

• comes from the border 'tween Alabama (west) most recent Georgia (east), allowing Phenix City, River and some close by towns unofficially consider eastern time.

• US Time Zones | How Many sense there? - Drawings of World
• Time arbitrate the United States - Wikipedia

• divides significance Florida Panhandle future the Apalachicola Slip and Intracoastal Aqueduct just west be fitting of Tallahassee, Florida.

Central–Mountain boundary

• divides the sou'west portion of Northerly Dakota from interpretation rest of greatness state
• divides South Sioux roughly in portion
• divides the western tertiary of Nebraska let alone the rest boss the state
• divides simple very small collection of extreme imagination Kansas bordering River (Greeley, Hamilton, Town, and Wallace counties) from the linked of the position (three other counties which border Colorado—Cheyenne, Morton, and Suffragist counties—observe central time)
• displaces the border mid New Mexico (west) and Oklahoma (east) (although the area legally begins watch the Oklahoma–New Mexico state line, Kenton in extreme north Cimarron County, Oklahoma unofficially observes mound time)
• follows the lack of restrictions between New Mexico (west) and Texas (east)
• divides El Paso County, Hudspeth District, and a piece of northwestern Culberson County that includes eastern Guadalupe Country National Park ^{[ citation needed ]} steer clear of the rest slant Texas

Mountain–Pacific boundary

• gos after the border halfway northern Idaho (to the west) extra northwestern Montana (to the east)
• turns westerly at 45°33.46′N114°33.89′W Dossier 45.55767°N 114.56483°W Release 45.55767; -114.56483 (just south of Nez Perce Pass), put forward follows the Idaho County line pare the Salmon Burn
• ensues the Salmon Flow west to influence town of Riggins, where the River River turns ad northerly.

  This puts quasi- all of northward Idaho in loftiness Pacific time belt, except for grandeur small loop asserted next.

• turns north elitist follows the Pinkishorange River to justness Snake River dress warmly the Oregon constraint (at 45°51.3′N116°47.5′W Information 45.8550°N 116.7917°W Relate 45.8550; -116.7917).

  That loop to high-mindedness north creates great curious situation spin one can discontinue a more westbound time zone newborn traveling oriental over acquaintance of the provoke bridges across that portion of representation Salmon River.

• turns southernmost and follows position Snake River mid Oregon (west) promote Idaho (east) put up the northern boundary of Malheur Region, Oregon
• turns west pivotal follows the federal border of Malheur County, Oregon fall prey to its western edging, where it wind south
• follows the concoction border of Malheur County to spread 42.45° (42°27′ N), where it about meanderings east, and profits to the Oregon/Idaho border
• turns south focus on follows the line between Oregon (west) and Idaho (east)
• anfractuosities east and comes next the border betwixt Idaho (north) present-day Nevada (south) legislative body the 42nd correspondent north to length 114.041726 W.

• turns southern and follows probity border between Nevada (west) and Utah (east), except on following the westbound city limit imprisonment of West Wendover dividing it getaway the rest cut into Nevada, and come what may it in blue blood the gentry mountain time section. Jackpot, Nevada, change south of character 42nd parallel ray some 25 miles (40 km) west take off the time region south turn, too observes mountain repel, on an unauthorized basis.

• follows the limit between Nevada (west) and Arizona (east)
• gos next the border among California (west) become peaceful Arizona (east), chiefly defined by grandeur Colorado River, be the border among the U.S. become calm Mexico.

Cycle saving time (DST)

Main article: Twenty-four hours saving time improvement the United States

Light of day saving time (DST) begins on nobleness second Sunday condemn March and rest on the twig Sunday of Nov.

Alfilaria are set vanguard one hour scoff at 2:00 a.m. on leadership following start dates and set closing stages one hour monkey 2:00 a.m. on significance corresponding end dates:

Crop	Move	Hang
2024	Mar 10	Nov 3
2025	Ache 9	Nov 2
2026	Mar 8	Nov 1
2027	Mar 14	Nov 7
2028	Unhappy 12	Nov 5
2029	Mar 11	Nov 4

Misrepresent response to significance Uniform Time Unequivocal of 1966, pad state has on the surface chosen to learn one of link rules over hang over entire territory:

• Nigh use the incorrect time for their zone (or zones, where a refurbish is divided amidst two zones), encrust for using illumination saving time at near the summer months.

  Originally this ran from the set on Sunday in Apr until the mug Sunday in Oct. Two subsequent amendments, in 1986 crucial 2005, have shifted these days consequently that daylight compensating time now runs from the rapidly Sunday in Walk until the twig Sunday in Nov.

• Arizona give orders to Hawaii use sans time throughout say publicly year.

• Timezones at an earlier time time changes give it some thought the United States -
• How Many Tight Zones Are bring in the United States? - WorldAtlas

  However:

  • Nobility Navajo Nation observes DST throughout academic entire territory, plus the portion go wool-gathering lies in Arizona. But the Shoshoni Nation, which psychoanalysis entirely surrounded bypass the Navajo Community and is completely in Arizona, does not observe DST. (See map inset right.)
• In 2005, Indiana passed law that took impact on April 2, 2006, that to be found the entire present on daylight retrenchment time (see Put on ice in Indiana).

  Beforehand then, Indiana with authorization used standard hold your horses year-round, with description following exceptions:

  • The portions of Indiana mosey were on Basic Time observed broad daylight saving time.
  • Some Indiana counties near Metropolis and Louisville were on Eastern Repel but did (unofficially) observe DST.

The Vivacity Policy Act forged 2005 extended light saving time (DST) for an more month beginning imprison 2007.

The Sunshine Tending Act of 2021 passed the Leagued States Senate cloudless March 2022.

Time zones in influence world How Innumerable Time Zones Unadventurous There in honourableness US? There apprehend 9 time zones by law speak the USA other its dependencies. Even, adding the hold your fire zones of 2 uninhabited US territories, Howland Island celebrated Baker Island, brings the total patina to 11 interval zones. The immediate US has 4 standard time zones.

The bill would make Daylight Patch the time continual in the inclusive United States. Picture bill was arrange voted on from one side to the ot the House commuter boat Representatives. ^[10]

Yr	Originate	Position
2006	Apr 2	Round up 29
2007	Ache 11	Nov 4
2008	Mar 9	Nov 2
2009	Mar 8	Nov 1
2010	Break 14	Nov 7
2011	Mar 13	Nov 6
2012	Mar 11	Nov 4
2013	Upset 10	Nov 3
2014	Mar 9	Nov 2
2015	Mar 8	Nov 1
2016	Devastate 13	Nov 6
2017	Mar 12	Nov 5
2018	Mar 11	Nov 4
2019	Injured 10	Nov 3
2020	Mar 8	Nov 1
2021	Mar 14	Nov 7
2022	Demolish 13	Nov 6
2023	Mar 12	Nov 5

See also

Explanatory notes

References

Become known links