The Mountain Time Zone of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

keeps time by subtracting seven hours from

Coordinated Universal Time Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communicat ...

(UTC) when

standard time Standard time is the synchronization of clocks within a geographical region to a single time standard, rather than a local mean time standard. Generally, standard time agrees with the local mean time at some meridian that passes through the r ...

( UTC−07:00) is in effect, and by subtracting six hours during

daylight saving time Daylight saving time (DST), also referred to as daylight savings time, daylight time (Daylight saving time in the United States, United States and Daylight saving time in Canada, Canada), or summer time (British Summer Time, United Kingdom, ...

( UTC−06:00). The clock time in this zone is based on the

mean solar time Solar time is a calculation of the passage of time based on the position of the Sun in the sky. The fundamental unit of solar time is the day, based on the synodic rotation period. Traditionally, there are three types of time reckoning based ...

at the 105th meridian west of the Greenwich Observatory. In the United States, the exact specification for the location of

time zone A time zone is an area which observes a uniform standard time for legal, Commerce, commercial and social purposes. Time zones tend to follow the boundaries between Country, countries and their Administrative division, subdivisions instead of ...

s and the dividing lines between zones is set forth in the

Code of Federal Regulations In the law of the United States, the ''Code of Federal Regulations'' (''CFR'') is the codification of the general and permanent regulatory law, regulations promulgated by the executive departments and agencies of the federal government of the ...

at 49 CFR 71. In the United States, Canada, and Mexico, this time zone is generically called Mountain Time (MT). Specifically, it is Mountain Standard Time (MST) when observing standard time, and Mountain Daylight Time (MDT) when observing daylight saving time. The term refers to the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

, which range from

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

. In Mexico, this time zone is known as the or ('Pacific Zone'). In the United States and Canada, the Mountain Time Zone is to the east of the

Pacific Time Zone The Pacific Time Zone (PT) is a time zone encompassing parts of western Canada, the western United States, and western Mexico. Places in this zone observe standard time by subtracting eight hours from Coordinated Universal Time ( UTC−08:00 ...

and to the west of the

Central Time Zone The North American Central Time Zone (CT) is a time zone in parts of Canada, the United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It ...

. In some areas, starting in 2007, the local time changes from MST to MDT at 2am MST to 3am MDT on the second Sunday in March and returns at 2am MDT to 1am MST on the first Sunday in November. Most of Mexico, and most of

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

in the United States, do not observe daylight saving time (DST), and during the spring, summer, and autumn months they are on the same time as

Pacific Daylight Time The Pacific Time Zone (PT) is a time zone encompassing parts of western Canada, the western United States, and western Mexico. Places in this zone observe standard time by subtracting eight hours from Coordinated Universal Time ( UTC−08:00). ...

. The

Navajo Nation The Navajo Nation (), also known as Navajoland, is an Indian reservation of Navajo people in the United States. It occupies portions of northeastern Arizona, northwestern New Mexico, and southeastern Utah. The seat of government is located in ...

is the only part of Arizona that observes DST. Its territory lies mostly within Arizona but extends into

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

and

(both observe DST statewide). Meanwhile, the Hopi Reservation, despite being completely surrounded by the Navajo Nation, does not observe DST, and neither do some Arizona state offices located within the Navajo Nation. The largest city in the Mountain Time Zone is

Phoenix, Arizona Phoenix ( ) is the List of capitals in the United States, capital and List of cities and towns in Arizona#List of cities and towns, most populous city of the U.S. state of Arizona. With over 1.6 million residents at the 2020 census, it is the ...

; the

Phoenix metropolitan area The Phoenix metropolitan area, also known as the Valley of the Sun, the Salt River Valley, metro Phoenix, or The Valley, is the largest metropolitan statistical area in the Southwestern United States, with its largest principal city being the c ...

is the largest metropolitan area in the zone. The largest city that observes daylight saving time is Juárez, Chihuahua, Mexico.

Canada

One province and two territories are fully contained in the Mountain Time Zone: *

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

Northwest Territories The Northwest Territories is a federal Provinces and territories of Canada, territory of Canada. At a land area of approximately and a 2021 census population of 41,070, it is the second-largest and the most populous of Provinces and territorie ...

Yukon Yukon () is a Provinces and territories of Canada, territory of Canada, bordering British Columbia to the south, the Northwest Territories to the east, the Beaufort Sea to the north, and the U.S. state of Alaska to the west. It is Canada’s we ...

(no DST) On September 24, 2020, Yukon switched to the Mountain Standard Time year-round. Therefore, clocks in Yukon and Alberta are the same in the winter, and Alberta is one hour ahead in summer. Previously, the territory had used the Pacific Time Zone with daylight saving time: UTC−8 in winter and UTC−7 in summer. One province and one territory are split between the Mountain Time Zone and the

: *

– northeastern and southeastern regions *

–

Tungsten Tungsten (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a metal found naturally on Earth almost exclusively in compounds with other elements. It was identified as a distinct element in 1781 and first ...

One territory and one province are split between the Mountain Time Zone and the

: *

Nunavut Nunavut is the largest and northernmost Provinces and territories of Canada#Territories, territory of Canada. It was separated officially from the Northwest Territories on April 1, 1999, via the ''Nunavut Act'' and the Nunavut Land Claims Agr ...

: Kitikmeot Region *

Saskatchewan Saskatchewan is a Provinces and territories of Canada, province in Western Canada. It is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and to the south by the ...

Lloydminster Lloydminster is a city in Canada which has the unusual geographic distinction of straddling the provincial border between Alberta and Saskatchewan. The city is incorporated by both provinces as a single city with a single municipal administra ...

and vicinity

Mexico

As of October 30, 2022, Mexico abandoned

, with certain exceptions. The following states have an offset equal to Mountain Standard Time: :*

Baja California Sur Baja California Sur, officially the Free and Sovereign State of Baja California Sur, is a state in Mexico. It is the 31st and last state to be admitted, in 1974. It is also the second least populated Mexican state and the ninth-largest state by ...

:* Nayarit: except for the Bahía de Banderas municipality, which uses the Central Time Zone. :*

Sonora Sonora (), officially Estado Libre y Soberano de Sonora (), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is divided into Municipalities of Sonora, 72 ...

Sinaloa Sinaloa (), officially the (), is one of the 31 states which, along with Mexico City, compose the Federal Entities of Mexico. It is divided into 18 municipalities, and its capital city is Culiacán Rosales. It is located in northwest Mexic ...

:* Chihuahua: Observes Daylight Savings Time, only in northwestern border municipalities ( Janos, Ascensión, Juárez, Guadalupe, and Práxedis Gilberto Guerrero) :* Revillagigedo Islands (

Colima Colima, officially the Free and Sovereign State of Colima, is among the 31 states that make up the 32 Federal Entities of Mexico. It shares its name with its capital and main city, Colima. Colima is a small state of western Mexico on the cen ...

): three of the four islands have the same time as Mountain Time Zone: Socorro Island, San Benedicto Island and Roca Partida. The following states have an offset equal to Mountain Daylight Time:

United States

Six states are fully contained in the Mountain Time Zone: *

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

(does not use daylight saving time except for

) Three states are split between the Mountain Time Zone and the

. The following locations observe Mountain Time: *

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

: Southern Idaho and the portion of Idaho County south of the Salmon River *

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

: the majority of Malheur County *

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

: West Wendover Five states are split between the Mountain Time Zone and the

. The following locations observe Mountain Time: *

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

: Sherman, Wallace, Greeley and

Hamilton Hamilton may refer to: * Alexander Hamilton (1755/1757–1804), first U.S. Secretary of the Treasury and one of the Founding Fathers of the United States * ''Hamilton'' (musical), a 2015 Broadway musical by Lin-Manuel Miranda ** ''Hamilton'' (al ...

counties *

Nebraska Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...

: western one third *

North Dakota North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...

: the southwest corner counties ( Adams, Billings, Bowman, Golden Valley, Grant, Hettinger,

Slope In mathematics, the slope or gradient of a Line (mathematics), line is a number that describes the direction (geometry), direction of the line on a plane (geometry), plane. Often denoted by the letter ''m'', slope is calculated as the ratio of t ...

, Stark) observe MST. The counties of McKenzie, Dunn, and

Sioux The Sioux or Oceti Sakowin ( ; Dakota/ Lakota: ) are groups of Native American tribes and First Nations people from the Great Plains of North America. The Sioux have two major linguistic divisions: the Dakota and Lakota peoples (translati ...

are split. *

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...

: western half *

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

: El Paso, Hudspeth, and northwestern Culberson counties

Major metropolitan areas

Alphabetical list of major cities located within the Mountain Time Zone. Cities in bold do not observe daylight saving time: *

Albuquerque, New Mexico Albuquerque ( ; ), also known as ABQ, Burque, the Duke City, and in the past 'the Q', is the List of municipalities in New Mexico, most populous city in the U.S. state of New Mexico, and the county seat of Bernalillo County, New Mexico, Bernal ...

Billings, Montana Billings is the most populous Lists of populated places in the United States, city in the U.S. state of Montana, with a population of 117,116 as of the 2020 United States census, 2020 census. Located in the south-central portion of the state, i ...

Boise, Idaho Boise ( ) is the List of capitals in the United States, capital and List of cities in Idaho, most populous city of the U.S. state of Idaho. As of the 2020 United States census, 2020 census, there were 235,685 people residing in the city. Loca ...

Boulder, Colorado Boulder is a List of municipalities in Colorado#Home rule municipality, home rule city in Boulder County, Colorado, United States, and its county seat. With a population of 108,250 at the 2020 United States census, 2020 census, it is the most ...

Calgary Calgary () is a major city in the Canadian province of Alberta. As of 2021, the city proper had a population of 1,306,784 and a metropolitan population of 1,481,806 making it the third-largest city and fifth-largest metropolitan area in C ...

, Alberta *

Cheyenne, Wyoming Cheyenne ( or ) is the List of capitals in the United States, capital and List of municipalities in Wyoming, most populous city of the U.S. state of Wyoming. It is the county seat of Laramie County, Wyoming, Laramie County, with 65,132 reside ...

Ciudad Juárez Ciudad Juárez ( , ; "Juárez City"), commonly referred to as just Juárez (Lipan language, Lipan: ''Tsé Táhú'ayá''), is the most populous city in the Administrative divisions of Mexico, Mexican state of Chihuahua (state), Chihuahua. It was k ...

, Chihuahua *

Ciudad Obregón Ciudad Obregón is a city in southern Sonora. It is the state's second largest city after Hermosillo and serves as the municipal seat of Cajeme. As of 2020, the city has a population of 436,484. Ciudad Obregón is south of the country's U.S.� ...

, Sonora *

Colorado Springs, Colorado Colorado Springs is the most populous city in El Paso County, Colorado, United States, and its county seat. The city had a population of 478,961 at the 2020 United States census, 2020 census, a 15.02% increase since 2010 United States Census, 2 ...

Culiacán Culiacán, officially Culiacán Rosales, is a city in northwestern Mexico, the capital and largest city of both Culiacán Municipality and the state of Sinaloa. The city was founded on 29 September 1531 by the Spanish conquistadors Lázaro de ...

, Sinaloa * Metropolitan Denver ** Arvada, Colorado **

Aurora, Colorado Aurora (, ) is a List of municipalities in Colorado#Home rule municipality, home rule city located in Arapahoe County, Colorado, Arapahoe, Adams County, Colorado, Adams, and Douglas County, Colorado, Douglas List of counties in Colorado, counti ...

Centennial, Colorado Centennial is a home rule city located in Arapahoe County, Colorado, United States. The city population was 108,418 at the 2020 United States census, making Centennial the 11th most populous municipality in Colorado. Centennial is a principal ...

Denver Denver ( ) is a List of municipalities in Colorado#Consolidated city and county, consolidated city and county, the List of capitals in the United States, capital and List of municipalities in Colorado, most populous city of the U.S. state of ...

Lakewood, Colorado Lakewood is the List of municipalities in Colorado#Home rule municipality, home rule municipality that is the List of municipalities in Colorado, most populous municipality in Jefferson County, Colorado, United States. The city population was 15 ...

** Westminster, Colorado *

Edmonton Edmonton is the capital city of the Provinces and territories of Canada, Canadian province of Alberta. It is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Central Alberta ...

, Alberta *

El Paso, Texas El Paso (; ; or ) is a city in and the county seat of El Paso County, Texas, United States. The 2020 United States census, 2020 population of the city from the United States Census Bureau, U.S. Census Bureau was 678,815, making it the List of ...

Flagstaff, Arizona Flagstaff ( ), known locally as Flag, is the county seat of Coconino County, Arizona, in the southwestern United States. As of the 2020 United States census, the city's population was 76,831. Flagstaff is the principal city of the Coconino Cou ...

Fort Collins, Colorado Fort Collins is a List of municipalities in Colorado#Home rule municipality, home rule municipality in Larimer County, Colorado, United States, and its county seat. The population was 169,810 at the 2020 United States census, 2020 census, an i ...

* Greeley, Colorado * Hermosillo, Sonora * La Paz, Baja California Sur * Lake Havasu City, Arizona *

Las Cruces, New Mexico Las Cruces (; ; lit. 'the crosses') is the List of municipalities in New Mexico, second-most populous city in the U.S. state of New Mexico and the county seat, seat of Doña Ana County, New Mexico, Doña Ana County. As of the 2020 United States ce ...

Lethbridge Lethbridge ( ) is a city in the province of Alberta, Canada. With a population of 106,550 in the 2023 Alberta municipal censuses, 2023 municipal census, Lethbridge became the fourth Alberta city to surpass 100,000 people. The nearby Canadian ...

, Alberta *

Los Mochis Los Mochis () is a coastal city in northern Sinaloa, Mexico. It serves as the municipal seat of the municipality of Ahome. As of the 2010 census, the population was 362,613, which was 61 percent of the municipality's population. Los Mochis is th ...

, Sinaloa *

Mazatlán Mazatlán () is a city in the Mexican list of states of Mexico, state of Sinaloa. The city serves as the municipal seat for the surrounding , known as the Mazatlán Municipality. It is located on the Pacific Ocean, Pacific coast across from th ...

, Sinaloa *

Missoula, Montana Missoula ( ) is a city in and the county seat of Missoula County, Montana, United States. It is located along the Clark Fork River near its confluence with the Bitterroot and Blackfoot rivers in western Montana and at the convergence of five ...

* Nogales, Sonora * Metropolitan Phoenix ** Chandler, Arizona **

Gilbert, Arizona Gilbert is a town in Maricopa County, Arizona, United States. Located southeast of Phoenix, Arizona, Phoenix, Gilbert is home to 288,128 residents. It is the fifth-most populous municipality in Arizona and is considered a suburb of Phoenix. I ...

Glendale, Arizona Glendale () is a city in Maricopa County, Arizona, United States. Located about nine miles northwest of the state capital Phoenix, Glendale is known for State Farm Stadium, which is the home of the Arizona Cardinals football team. The city al ...

Mesa, Arizona Mesa ( ) is a city in Maricopa County, Arizona, United States. The population was 504,258 at the 2020 census. It is the List of municipalities in Arizona, third-most populous city in Arizona, after Phoenix, Arizona, Phoenix and Tucson, Arizona, T ...

** Peoria, Arizona **

Surprise, Arizona Surprise is a city in Maricopa County, in the U.S. state of Arizona. The population was 143,148 at the 2020 census, up from 117,517 in 2010 and just 30,848 in 2000. Surprise is the spring training location of the Kansas City Royals and the ...

Tempe, Arizona Tempe ( ; ''Oidbaḍ'' in O'odham language, O'odham) is a city in Maricopa County, Arizona, United States, with the Census Bureau reporting a 2020 population of 180,587. The city is named after the Vale of Tempe in Greece. Tempe is located in t ...

Pueblo, Colorado Pueblo ( ) is a List of municipalities in Colorado#Home rule municipality, home rule municipality that is the county seat of and the List of municipalities in Colorado, most populous municipality in Pueblo County, Colorado, United States. The ...

Rapid City, South Dakota Rapid City is the county seat of Pennington County, South Dakota, United States. It is located on the eastern slope of the Black Hills in western South Dakota and was named after Rapid Creek (South Dakota), Rapid Creek, where the settlement deve ...

* Red Deer, Alberta * San Luis Río Colorado, Sonora *

Tepic Tepic () is the capital and largest city of the western Mexico, Mexican Political divisions of Mexico, state of Nayarit, as well as the seat of the Tepic Municipality. Located in the central part of the state, it stands at an altitude of above ...

, Nayarit *

Tucson, Arizona Tucson (; ; ) is a city in Pima County, Arizona, United States, and its county seat. It is the second-most populous city in Arizona, behind Phoenix, Arizona, Phoenix, with a population of 542,630 in the 2020 United States census. The Tucson ...

Wasatch Front The Wasatch Front is a major metropolitan region in the north-central part of the U.S. state of Utah. It consists of a chain of contiguous cities and towns stretched along the Wasatch Range from Santaquin in the south to Pleasant View in the n ...

Orem, Utah Orem is a city in Utah County, Utah, United States, in the northern part of the state. It is adjacent to Provo, Utah, Provo, Lindon, Utah, Lindon, and Vineyard, Utah, Vineyard and is approximately south of Salt Lake City. Orem is one of the pri ...

Provo, Utah Provo ( ) is a city in and the county seat of Utah County, Utah, United States. It is south of Salt Lake City along the Wasatch Front, and lies between the cities of Orem, Utah, Orem to the north and Springville, Utah, Springville to the south ...

Salt Lake City Salt Lake City, often shortened to Salt Lake or SLC, is the capital and most populous city of the U.S. state of Utah. It is the county seat of Salt Lake County, the most populous county in the state. The city is the core of the Salt Lake Ci ...

, Utah ** West Jordan, Utah ** West Valley City, Utah *

Yuma, Arizona Yuma is a city in and the county seat of Yuma County, Arizona, United States. The city's population was 95,548 at the 2020 census, up from the 2010 census population of 93,064. Yuma is the principal city of the Yuma, Arizona, Metropolitan ...

Notes

References

External links

World time zone map

History of U.S. time zones and UTC conversion

Official times across Mexico

U.S. time map
{{North American time zones Time zones Time in Canada Time in Mexico Time zones in the United States

Canada

Mexico

United States

Major metropolitan areas

See also

Notes

References

External links