Pacific Time Zone
Encyclopedia
Standard time
Standard time is the result of synchronizing clocks in different geographical locations within a time zone to the same time rather than using the local meridian as in local mean time or solar time. Historically, this helped in the process of weather forecasting and train travel. The concept...
by subtracting eight hours from Coordinated Universal Time
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
(UTC-8). The clock time in this zone is based on the mean solar time of the 120th meridian west
120th meridian west
The meridian 120° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole....
of the Greenwich Observatory. During daylight saving time
Daylight saving time
Daylight saving time —also summer time in several countries including in British English and European official terminology —is the practice of temporarily advancing clocks during the summertime so that afternoons have more daylight and mornings have less...
, its time offset
Time offset
The UTC offset is the time offset from Coordinated Universal Time . It is mostly given as hour or hour and minute. Many time zones employ two time offsets, one for standard time and one for daylight saving time...
is UTC-7.
In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, this time zone is generically called Pacific Time (PT). Specifically, it is Pacific Standard Time (PST) when observing standard time (Winter
Winter
Winter is the coldest season of the year in temperate climates, between autumn and spring. At the winter solstice, the days are shortest and the nights are longest, with days lengthening as the season progresses after the solstice.-Meteorology:...
), and Pacific Daylight Time (PDT) when observing daylight saving time (Summer
Summer
Summer is the warmest of the four temperate seasons, between spring and autumn. At the summer solstice, the days are longest and the nights are shortest, with day-length decreasing as the season progresses after the solstice...
). Most of Canada uses daylight saving time
Daylight saving time
Daylight saving time —also summer time in several countries including in British English and European official terminology —is the practice of temporarily advancing clocks during the summertime so that afternoons have more daylight and mornings have less...
. In Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
the UTC-8 time zone is known as the Northwest Zone, which formerly was synchronized with the U.S. PDT daylight saving schedule.
The zone is one hour ahead of the Alaska Time Zone
Alaska Time Zone
The Alaska Time Zone observes standard time by subtracting nine hours from Coordinated Universal Time . During daylight saving time its time offset is only eight hours . The clock time in this zone is based on the mean solar time of the 135th meridian west of the Greenwich Observatory.The zone...
, one hour behind the Mountain Time Zone
Mountain Time Zone
The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time, also known as Greenwich Mean Time, during the shortest days of autumn and winter , and by subtracting six hours during daylight saving time in the spring, summer, and early autumn...
and three hours behind the Eastern Time Zone.
United States
The following states or areas are part of the Pacific Time Zone:- CaliforniaCaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
- all - Washington - all
- OregonOregonOregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
– all, except for northern three quarters of Malheur CountyMalheur County, OregonMalheur County is a county located in the southeast corner of the U.S. state of Oregon. It is included in the eight-county definition of Eastern Oregon. Most of the county observes the Mountain Time Zone, although the southern quarter of the county observes the Pacific Time Zone along with the...
, on Idaho border (the dividing line goes through the southwest corner of township 35 S, range 37 E, and lies at a latitude of approximately 42.4507448 N) - NevadaNevadaNevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
– all, except for the border town of West WendoverWest Wendover, NevadaWest Wendover is a city in Elko County, Nevada, United States. The population was 4,721 at the 2000 census. It is part of the Elko Micropolitan Statistical Area. West Wendover is located on the eastern border of Nevada and the western edge of the Great Salt Lake Desert, and is contiguous with...
(near Utah), which observes the Mountain Time Zone, and the border town of JackpotJackpot, NevadaJackpot is an unincorporated community in Elko County, Nevada, United States. The Zip Code Tabulation Area for its ZIP code, 89825, had a population of 1,189 as of the 2010 census. Located less than 1 mile from the Idaho border on U.S...
(near Idaho) which unofficially observes Mountain Time Zone - IdahoIdahoIdaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
– northern halfIdaho PanhandleThe Idaho Panhandle is the northern region of the U.S. State of Idaho that encompasses the ten northernmost counties of Benewah, Bonner, Boundary, Clearwater, Idaho, Kootenai, Latah, Lewis, Nez Perce, Shoshone. Residents of the panhandle refer to the region as North Idaho...
, north of Salmon RiverSalmon River (Idaho)The Salmon River is located in Idaho in the northwestern United States. The Salmon is also known as The River of No Return. It flows for through central Idaho, draining and dropping more than between its headwaters, near Galena Summit above the Sawtooth Valley in the Sawtooth National...
Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
is in the Mountain Time Zone
Mountain Time Zone
The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time, also known as Greenwich Mean Time, during the shortest days of autumn and winter , and by subtracting six hours during daylight saving time in the spring, summer, and early autumn...
but does not observe daylight saving time
Daylight saving time
Daylight saving time —also summer time in several countries including in British English and European official terminology —is the practice of temporarily advancing clocks during the summertime so that afternoons have more daylight and mornings have less...
(except in the Navajo Nation
Navajo Nation
The Navajo Nation is a semi-autonomous Native American-governed territory covering , occupying all of northeastern Arizona, the southeastern portion of Utah, and northwestern New Mexico...
), so while technically it is on Mountain Standard Time, it is effectively on Pacific Daylight Time from mid-March to early November.
Canada
In CanadaCanada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Pacific Time includes almost all of the province of British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
(except for the Highway 95 corridor and portions around Fort St. John, Dawson Creek
Dawson Creek, British Columbia
Dawson Creek is a small city in northeastern British Columbia, Canada. The municipality of had a population of 11,529 in 2009. Dawson Creek derives its name from the creek of the same name that runs through the community. The creek was named after George Mercer Dawson by a member of his land...
, Golden
Golden, British Columbia
Golden is a town in southeastern British Columbia, Canada, located west of Calgary, Alberta and east of Vancouver.-History:Much of the town's history is tied into the Canadian Pacific Railway and the logging industry...
and Creston
Creston, British Columbia
Creston is a town of 4,826 people in the Kootenay region of southeastern British Columbia, Canada. The town is located just a few kilometers north of the Porthill, Idaho border crossing into the United States and about a three-hour drive north from Spokane, Washington. It is about a one-hour drive...
), all of Yukon
Yukon
Yukon is the westernmost and smallest of Canada's three federal territories. It was named after the Yukon River. The word Yukon means "Great River" in Gwich’in....
and Tungsten
Tungsten, Northwest Territories
The townsite of Tungsten is located at Cantung Mine in the Northwest Territories. It is accessible from Watson Lake, Yukon. Tungsten was built in 1961 and the tungsten mine went into operation in 1962 as a large open pit mine high in the Mackenzie Mountains. It originally consisted of several small...
, Northwest Territories
Northwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
.
Mexico
In MexicoMexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, the state of Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
is completely within and the only part of Mexico in PST. Also the westernmost of the Revillagigedo Islands
Revillagigedo Islands
The Revillagigedo Islands or Revillagigedo Archipelago are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem...
, Clarion Island
Clarion Island
Isla Clarión, formerly called Santa Rosa, is the second largest, westernmost and most remote of the Revillagigedo Islands, west of Socorro Island and over from the Mexican mainland and an area ². It has three prominent peaks. The westernmost and tallest peak, Monte Gallegos, is high...
(in the state of Colima
Colima
Colima is one of the 31 states which, with the Federal District, make up the 32 Federal Entities of Mexico. It shares its name with its capital and main city, Colima....
), observes PST.
Daylight time
During summer months, most of ArizonaArizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, which is in the Mountain time zone but does not observe DST, is on the same time as neighboring states to the west which are on Pacific Daylight Time.
Through 2006, the local time (PST, UTC-8) changed to PDT (UTC-7) at 02:00 LST (local standard time) to 03:00 LDT (local daylight time) on the first Sunday in April, and returned at 02:00 LDT to 01:00 LST on the last Sunday in October.
Effective in the US in 2007 as a result of the Energy Policy Act of 2005, the local time changes from PST to PDT at 02:00 LST to 03:00 LDT on the second Sunday in March and the time returns at 02:00 LDT to 01:00 LST on the first Sunday in November. Canada would also acknowledge this change. In Mexico, beginning in 2010, the portion of the country in this time zone uses the extended dates, as do some other parts. The vast majority of Mexico, however, still uses the old dates.
Major cities
A rough estimate of the population of the entire time zone is 53 million (i.e., the populations of Washington, OregonOregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
, British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, and the Yukon
Yukon
Yukon is the westernmost and smallest of Canada's three federal territories. It was named after the Yukon River. The word Yukon means "Great River" in Gwich’in....
combined).
Over 1,000,000 residents
- Los Angeles, CaliforniaLos ÁngelesLos Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
, USA - San Diego, California, USA
- Tijuana, Baja CaliforniaTijuanaTijuana is the largest city on the Baja California Peninsula and center of the Tijuana metropolitan area, part of the international San Diego–Tijuana metropolitan area. An industrial and financial center of Mexico, Tijuana exerts a strong influence on economics, education, culture, art, and politics...
, Mexico
Over 800,000 residents
- San Francisco, California, USA
- San Jose, CaliforniaSan Jose, CaliforniaSan Jose is the third-largest city in California, the tenth-largest in the U.S., and the county seat of Santa Clara County which is located at the southern end of San Francisco Bay...
, USA
Over 400,000 residents
- Fresno, CaliforniaFresno, CaliforniaFresno is a city in central California, United States, the county seat of Fresno County. As of the 2010 census, the city's population was 510,365, making it the fifth largest city in California, the largest inland city in California, and the 34th largest in the nation...
, USA - Las Vegas, NevadaLas Vegas, NevadaLas Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...
, USA - Long Beach, CaliforniaLong Beach, CaliforniaLong Beach is a city situated in Los Angeles County in Southern California, on the Pacific coast of the United States. The city is the 36th-largest city in the nation and the seventh-largest in California. As of 2010, its population was 462,257...
, USA - Oakland, CaliforniaOakland, CaliforniaOakland is a major West Coast port city on San Francisco Bay in the U.S. state of California. It is the eighth-largest city in the state with a 2010 population of 390,724...
, USA - Portland, OregonPortland, OregonPortland is a city located in the Pacific Northwest, near the confluence of the Willamette and Columbia rivers in the U.S. state of Oregon. As of the 2010 Census, it had a population of 583,776, making it the 29th most populous city in the United States...
, USA - Seattle, Washington, USA
- Sacramento, CaliforniaSacramento, CaliforniaSacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...
, USA - Surrey, British ColumbiaSurrey, British ColumbiaSurrey is a city in the province of British Columbia, Canada. It is a member municipality of Metro Vancouver, the governing body of the Greater Vancouver Regional District...
, Canada - Vancouver, British ColumbiaVancouverVancouver is a coastal seaport city on the mainland of British Columbia, Canada. It is the hub of Greater Vancouver, which, with over 2.3 million residents, is the third most populous metropolitan area in the country,...
, Canada - Mexicali, Baja CaliforniaMexicaliMexicali is the capital of the State of Baja California, seat of the Municipality of Mexicali, and 2nd largest city in Baja California. The City of Mexicali has a population of 689,775, according to the 2010 census, while the population of the entire metropolitan area reaches 936,826.The city...
, Mexico
Over 200,000 residents
- Ensenada, Baja CaliforniaEnsenada, Baja CaliforniaEnsenada is a coastal city in Mexico and the third-largest city in Baja California. It is located south of San Diego on the Baja California Peninsula. The city is locally referred to as La Cenicienta del Pacífico, or, The Cinderella of the Pacific...
, Mexico - Anaheim, CaliforniaAnaheim, CaliforniaAnaheim is a city in Orange County, California. As of the 2010 United States Census, the city population was about 365,463, making it the most populated city in Orange County, the 10th most-populated city in California, and ranked 54th in the United States...
, USA - Bakersfield, CaliforniaBakersfield, CaliforniaBakersfield is a city near the southern end of the San Joaquin Valley in Kern County, California. It is roughly equidistant between Fresno and Los Angeles, to the north and south respectively....
, USA - Burnaby, British Columbia, Canada
- Fremont, CaliforniaFremont, CaliforniaFremont is a city in Alameda County, California. It was incorporated on January 23, 1956, from the merger of five smaller communities: Centerville, Niles, Irvington, Mission San Jose, and Warm Springs...
, USA - Glendale, CaliforniaGlendale, CaliforniaGlendale is a city in Los Angeles County, California, United States. As of the 2010 Census, the city population is 191,719, down from 194,973 at the 2000 census. making it the third largest city in Los Angeles County and the 22nd largest city in the state of California...
, USA - Henderson, NevadaHenderson, Nevada-Demographics:According to the 2000 census, there were 175,381 people, 66,331 households, and 47,095 families residing in the city. The population density was 2,200.8 people per square mile . There were 71,149 housing units at an average density of 892.8 per square mile...
, USA - Irvine, CaliforniaIrvine, CaliforniaIrvine is a suburban incorporated city in Orange County, California, United States. It is a planned city, mainly developed by the Irvine Company since the 1960s. Formally incorporated on December 28, 1971, the city has a population of 212,375 as of the 2010 census. However, the California...
, USA - Modesto, CaliforniaModesto, CaliforniaModesto is a city in, and is the county seat of, Stanislaus County, California. With a population of approximately 201,165 at the 2010 census, Modesto ranks as the 18th largest city in the state of California....
, USA - Oxnard, CaliforniaOxnard, CaliforniaOxnard is the 113th largest city in the United States, 19th largest city in California and largest city in Ventura County, California, by way of population. It is located at the western edge of the fertile Oxnard Plain, and is an important agricultural center, with its distinction as the...
, USA - Reno, NevadaReno, NevadaReno is the county seat of Washoe County, Nevada, United States. The city has a population of about 220,500 and is the most populous Nevada city outside of the Las Vegas metropolitan area...
, USA - Riverside, CaliforniaRiverside, CaliforniaRiverside is a city in Riverside County, California, United States, and the county seat of the eponymous county. Named for its location beside the Santa Ana River, it is the largest city in the Riverside-San Bernardino-Ontario metropolitan area of Southern California, 4th largest inland California...
, USA - San Bernardino, CaliforniaSan Bernardino, CaliforniaSan Bernardino is a city located in the Riverside-San Bernardino metropolitan area , and serves as the county seat of San Bernardino County, California, United States...
, USA - Santa Ana, CaliforniaSanta Ana, CaliforniaSanta Ana is the county seat and second most populous city in Orange County, California, and with a population of 324,528 at the 2010 census, Santa Ana is the 57th-most populous city in the United States....
, USA - Spokane, WashingtonSpokane, WashingtonSpokane is a city located in the Northwestern United States in the state of Washington. It is the largest city of Spokane County of which it is also the county seat, and the metropolitan center of the Inland Northwest region...
, USA - Stockton, CaliforniaStockton, CaliforniaStockton, California, the seat of San Joaquin County, is the fourth-largest city in the Central Valley of the U.S. state of California. With a population of 291,707 at the 2010 census, Stockton ranks as this state's 13th largest city...
, USA - Tacoma, WashingtonTacoma, WashingtonTacoma is a mid-sized urban port city and the county seat of Pierce County, Washington, United States. The city is on Washington's Puget Sound, southwest of Seattle, northeast of the state capital, Olympia, and northwest of Mount Rainier National Park. The population was 198,397, according to...
, USA