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Pacific Time Zone
 
 
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The Pacific Time Zone observes standard time
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....
 by subtracting eight hours from Coordinated Universal Time
Coordinated Universal Time

Coordinated Universal Time is a time standard based on International Atomic Time with leap seconds added at irregular intervals to compensate for the Earth's slowing rotation....
 (UTC-8
UTC-8

UTC-8 is a band of timezones separated from the Universal Coordinated Time by 8 hours....
). 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 Prime Meridian 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 is the convention of advancing clocks so that afternoons have more daylight and mornings have less. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in autumn....
, its time offset
Time offset

A time offset is defined by international convention as a number of hours and minutes from Coordinated Universal Time . Many time zones employ two time offsets, one for standard time and one for daylight saving time....
 is UTC-7
UTC-7

UTC-7 can be observed in:...
.

In the United States
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 and Canada
Canada

Canada is a country occupying most of northern North America, extending 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 one of the four seasons of temperate zones. Calculated astronomy, it begins on the solstice and ends on the equinox. It is the season with the shortest days and the lowest average temperatures....
), and Pacific Daylight Time (PDT) when observing daylight saving time (Summer
Summer

Summer generally refers to the warmest and most humid season between spring and autumn, from the summer solstice to the autumnal equinox. In the Northern Hemisphere, this falls from the June solstice to the September equinox, while in the Southern Hemisphere it falls from the December solstice to the March equinox....
).






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The Pacific Time Zone observes standard time
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....
 by subtracting eight hours from Coordinated Universal Time
Coordinated Universal Time

Coordinated Universal Time is a time standard based on International Atomic Time with leap seconds added at irregular intervals to compensate for the Earth's slowing rotation....
 (UTC-8
UTC-8

UTC-8 is a band of timezones separated from the Universal Coordinated Time by 8 hours....
). 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 Prime Meridian 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 is the convention of advancing clocks so that afternoons have more daylight and mornings have less. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in autumn....
, its time offset
Time offset

A time offset is defined by international convention as a number of hours and minutes from Coordinated Universal Time . Many time zones employ two time offsets, one for standard time and one for daylight saving time....
 is UTC-7
UTC-7

UTC-7 can be observed in:...
.

In the United States
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 and Canada
Canada

Canada is a country occupying most of northern North America, extending 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 one of the four seasons of temperate zones. Calculated astronomy, it begins on the solstice and ends on the equinox. It is the season with the shortest days and the lowest average temperatures....
), and Pacific Daylight Time (PDT) when observing daylight saving time (Summer
Summer

Summer generally refers to the warmest and most humid season between spring and autumn, from the summer solstice to the autumnal equinox. In the Northern Hemisphere, this falls from the June solstice to the September equinox, while in the Southern Hemisphere it falls from the December solstice to the March equinox....
). Canada follows United States daylight time. In Mexico
Mexico

The United Mexican States , commonly known as Mexico , is a federalism constitutionalism 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 Mexico....
 the UTC-8 time zone is known as the Northwest Zone (Zona Noroeste), 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 ....
, 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, sometimes called 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

In the United States
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
, the states of Washington
Washington

Washington is a U.S. state in the Pacific Northwest region of the United States. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute....
 and California
California

California is a U.S. state on the West Coast of the United States of the United States, along the Pacific Ocean. It is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and to the south the Mexico state of Baja California....
 are located entirely within the Pacific Time Zone. Nearly all of Nevada
Nevada

Nevada is a U.S. state located in the Western United States of the United States of America. The capital is Carson City and the largest city is Las Vegas, Nevada....
, except for the towns of West Wendover
West Wendover, Nevada

West Wendover is a city in Elko County, Nevada, Nevada, United States. The population was 4,721 at the United States Census 2000. It is part of the Elko, Nevada Elko micropolitan area....
 and Jackpot
Jackpot, Nevada

Jackpot is an unincorporated town in Elko County, Nevada, Nevada. In 2005 it was estimated to have a population of 1,416. Located less than 1 mile from the Idaho border on U.S....
, is on Pacific Time. Additionally, all of Oregon
Oregon

Oregon is a U.S. state in the Pacific Northwest region of the United States. The area was inhabited by many indigenous tribes before the arrival of traders, explorers and settlers....
 except for the greater part of Malheur County
Malheur County, Oregon

Malheur County is a List of counties in Oregon located in the southeast corner of the U.S. state of Oregon. The Oregon Geographic Names for Malheur River, which flows through it....
 and the northern part of Idaho
Idaho

The State of Idaho is a U.S. state in the Pacific Northwest region of the United States of America. The state's largest city and Capital is Boise, Idaho....
 (the Idaho Panhandle
Idaho Panhandle

The Idaho Panhandle is the northern region of the U.S. State of Idaho that encompasses the ten northernmost List of Idaho counties of Benewah County, Idaho, Bonner County, Idaho, Boundary County, Idaho, Clearwater County, Idaho, Idaho County, Idaho, Kootenai County, Idaho, Latah County, Idaho, Lewis County, Idaho, Nez Perce County, Idaho, Sho...
) are also in the zone. The exact specification for the location of time zone
Time zone

A time zone is a region of the earth that has uniform standard time, usually referred to as the local time. By convention, time zones compute their local time as an offset from Coordinated Universal Time ....
s and the dividing line between zones is set forth in the Code of Federal Regulations
Code of Federal Regulations

File:Codeoffederalregulations.jpgThe Code of Federal Regulations is the codification of the general and permanent rules and regulations published in the Federal Register by the executive departments and agencies of the Federal Government of the United States....
 at 49 CFR 71. The boundary between Pacific and Mountain in the United States is set forth at 49 CFR 71.9, and is listed in and formats.

Canada

In Canada
Canada

Canada is a country occupying most of northern North America, extending 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 territories of Canada and is famed for its natural beauty, as reflected in its Latin motto, Splendor sine occasu ....
 (except for the Highway 95 corridor and portions around Fort St. John, Dawson Creek
Dawson Creek, British Columbia

The City of Dawson Creek is a small city in northeastern British Columbia, Canada. The municipality of had a population of 11,811 in 2007. Dawson Creek derives its name from the creek of the same name that runs through the community....
 and Creston
Creston, British Columbia

Creston is a town of 4,826 people in the Kootenays 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, Washington....
), all of the Yukon
Yukon

Yukon is the westernmost and smallest of Canada three Territories of Canada. It was named after the Yukon River, Yukon meaning "Great River" in Gwich?in language....
 Territory 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, Yukon. Tungsten was built in 1961 and the tungsten mine went into operation in 1962 as a large Open-pit mining high in the Mackenzie Mountains....
, Northwest Territories
Northwest Territories

The Northwest Territories are a provinces and territories of Canada of Canada.Located in northern Canada, it borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, Alberta and Saskatchewan to the south....
.

Mexico

In Mexico
Mexico

The United Mexican States , commonly known as Mexico , is a federalism constitutionalism 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 Mexico....
, the state of Baja California
Baja California

Baja California is the northernmost States of Mexico of Mexico. Before becoming a state in 1953, the area was known as the North Territory of Baja California....
 is wholly within and the only part of Mexico in the Northwest Zone. Also the westernmost of the Revillagigedo Islands
Revillagigedo Islands

The Revillagigedo Islands are a group of four volcanic islands in the Pacific Ocean, known for their unique ecosystem. They have been part of Manzanillo, Colima Municipalities of Colima of the Mexico mexican state of Colima since 1861, but are nevertheless under Mexican federal jurisdiction, and lie 386 km southwest of Cabo San Luca...
 (Colima
Colima

Colima is a state in western Mexico. It shares its name with its capital and main city, Colima, Colima.Colima is a small state, sharing a border with the Mexican states of Jalisco to the north and east, and Michoac?n to the south....
), Clarion Island
Clarion Island

Isla Clari?n, formerly called Santa Rosa, is the second largest, westernmost and most remote of the Revillagigedo Islands, 314 km west of Socorro Island and over 700 km from the Mexican mainland....
 uses the Northwest Zone.

Daylight time

During summer months, Sonora
Sonora

Sonora is one of the 31 States of Mexico and is located in the northwest of the country....
 and most of Arizona
Arizona

The State of Arizona is a U.S. state located in the Southwestern United States of the United States. The capital and largest city is Phoenix, Arizona....
, which is in the Mountain time zone (Pacific zone for Sonora) but does not observe DST, they are 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 2007, the local time changes from PST to PDT at 02:00 LST to 03:00 LDT on the second Sunday in March and returns at 02:00 LDT to 01:00 LST on the first Sunday in November, except in Mexico, where the previous dates are still in effect.

Major cities


A rough estimation of the population of the entire time zone is 53,462,949. That is, the populations of Washington
Washington

Washington is a U.S. state in the Pacific Northwest region of the United States. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute....
, Oregon
Oregon

Oregon is a U.S. state in the Pacific Northwest region of the United States. The area was inhabited by many indigenous tribes before the arrival of traders, explorers and settlers....
, Nevada
Nevada

Nevada is a U.S. state located in the Western United States of the United States of America. The capital is Carson City and the largest city is Las Vegas, Nevada....
, California
California

California is a U.S. state on the West Coast of the United States of the United States, along the Pacific Ocean. It is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and to the south the Mexico state of Baja California....
, Baja California
Baja California

Baja California is the northernmost States of Mexico of Mexico. Before becoming a state in 1953, the area was known as the North Territory of Baja California....
, British Columbia
British Columbia

British Columbia is the westernmost of Canada's Provinces and territories of Canada and is famed for its natural beauty, as reflected in its Latin motto, Splendor sine occasu ....
, and Yukon Territory combined.

Over 1,000,000 residents
  • Los Angeles, California
    Los Angeles, California

    Los Angeles is the largest city in the U.S. state of California and the List of United States cities by population in the United States. Often abbreviated as L.A. and nicknamed The City of Angels, Los Angeles is rated as a beta global city, has an estimated population of 3.8 million and spans over in Southern California....
    , USA
  • San Diego, California
    San Diego, California

    San Diego is the second largest city in California and the List of United States cities by population, located along the Pacific Ocean on the West Coast of the United States of the Western United States....
    , USA
  • Tijuana, Baja California
    Tijuana

    Tijuana , is the largest city of the Mexican state of Baja California, situated on the United States?Mexico border adjacent to its sister city of San Diego, California....
    , Mexico


Over 700,000 residents
  • San Francisco, California
    San Francisco, California

    The City and County of San Francisco is the fourth most populous city in California and the List of United States cities by population in the United States, with a 2007 estimated population of 799,183....
    , USA
  • San Jose, California
    San Jose, California

    San Jose or San Jos? is the List of cities in California city in California and the List of United States cities by population in the United States....
    , USA
  • Mexicali, Baja California, Mexico


Over 400,000 residents
  • Ensenada, Baja California
    Ensenada, Baja California

    Ensenada is the third-largest city in the Mexico States of Mexico ofBaja California. It is located 116 km south of Tijuana, at . The city had a 2005 census population of 460,075....
    , Mexico
  • Fresno, California
    Fresno, California

    Fresno is a city in California, USA, the county seat of Fresno County, California, and the second largest inland city in the state, after San Jose, California....
    , USA
  • Las Vegas, Nevada
    Las Vegas, Nevada

    Las Vegas is the most populous city in the U.S. state of Nevada, the seat of Clark County, Nevada, and an internationally renowned major resort city for gambling, shopping, and entertainment....
    , USA
  • Long Beach, California
    Long Beach, California

    Long Beach is a large city located in southern California, USA, on the Pacific Ocean coast. It is situated in Los Angeles County, about south of downtown Los Angeles....
    , USA
  • Oakland, California
    Oakland, California

    Oakland , founded in 1852, is the eighth-largest city in the U.S. state of California and the county seat of Alameda County, California. Oakland is approximately 8 miles east of San Francisco and the cities are separated by San Francisco Bay....
    , USA
  • Portland, Oregon
    Portland, Oregon

    Portland is a city located in the Northwestern United States United States, near the confluence of the Willamette River and Columbia River rivers in the state of Oregon....
    , USA
  • Seattle, Washington
    Seattle, Washington

    Seattle is the most populous city in the US state of Washington and the Northwestern United States. The encompassing Seattle metropolitan area is the 15th largest in the United States, and the largest in the Pacific Northwest....
    , USA
  • Sacramento, California
    Sacramento, California

    Sacramento is the Capital of the United States U.S. state of California, and the county seat of Sacramento County, California. Located along the Sacramento River and just south of the American River's confluence in California's expansive California Central Valley, it is the seventh-largest city in California.....
    , USA
  • Surrey, British Columbia
    Surrey, British Columbia

    Surrey is a Canada city in the province of British Columbia, Canada, that lies within the Metro Vancouver district, and geographically at the centre of the larger region known as the Lower Mainland of BC....
    , Canada
  • Vancouver, British Columbia, Canada


Over 200,000 residents
  • Anaheim, California
    Anaheim, California

    Anaheim is a city in Orange County, California. As of January 1, 2008, the city population was about 346,823, making it the 10th most-populated city in California and ranked 54th in the United States....
    , USA
  • Bakersfield, California
    Bakersfield, California

    Bakersfield is a large city at the southern end of the San Joaquin Valley in Kern County, California, California, United States. It is one of the fastest-growing large-population cities in the USA, and is located roughly equidistant between Los Angeles and Fresno, California, to the south and north respectively....
    , USA
  • Burnaby, British Columbia
    Burnaby, British Columbia

    Burnaby, British Columbia, Canada, is the city immediately east of Vancouver. It is the third-largest city in British Columbia by population, surpassed only by nearby Surrey, British Columbia and Vancouver itself....
    , Canada
  • Fremont, California
    Fremont, California

    Fremont is a city in Alameda County, California, California; it was incorporated on January 23, 1956, from the merger of five smaller communities: #Centerville, #Irvington, #Mission San Jose, #Niles, and #Warm Springs....
    , USA
  • Henderson, Nevada
    Henderson, Nevada

    Henderson is a city in Clark County, Nevada, Nevada, United States in the Las Vegas metropolitan area; it is located mainly to the southeast. The population was estimated at 249,386 by the 2007 United States Census Bureau....
    , USA
  • Irvine, California
    Irvine, California

    Irvine is an incorporated city in Orange County, California, United States. It is a planned city, mainly developed by the Irvine Company since the 1960s....
    , USA
  • Modesto, California
    Modesto, California

    Modesto is the county seat of Stanislaus County, California. As of January 1, 2008 the estimated population is 209,936. Its population has boomed for the last decade, becoming the sixteenth largest city in the state and the sixth largest inland city in the state behind Stockton, California, Bakersfield, Riverside, California, Sacramento, and...
    , USA
  • Reno, Nevada
    Reno, Nevada

    Reno is the county seat of Washoe County, Nevada, Nevada, United States. A 2006 estimate indicated that the city's population had increased to 214,853, but ranked Reno as the third largest city in the state following Las Vegas, Nevada, and Henderson, Nevada....
    , USA
  • Riverside, California
    Riverside, California

    Riverside is a large city located in the Inland Empire in Southern California. It is also the county seat of Riverside County, California, California, United States....
    , USA
  • Santa Ana, California
    Santa Ana, California

    Founded in 1869, Santa Ana is the most populous city in Orange County, California, USA and is the county seat, with an estimated 353,184 people....
    , USA
  • Spokane, Washington
    Spokane, Washington

    Spokane is a city located in the Northwestern United States in the state of Washington. Spokane is the largest city and county seat of Spokane County, as well as the metropolitan center of the Inland Northwest region....
    , USA
  • Stockton, California
    Stockton, California

    Stockton is a city in California and the county seat of San Joaquin County, California . Stockton's population estimate for January 1, 2008, according to the California Department of Finance, is 290,141....
    , USA
  • Tacoma, Washington
    Tacoma, Washington

    Tacoma is a mid-sized urban port city in 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, Washington, and northwest of Mount Rainier National Park....
    , USA
  • Victoria, British Columbia
    Victoria, British Columbia

    Victoria is the capital city of British Columbia. Located on the southern tip of Vancouver Island, Victoria is a major tourism destination seeing more than 3.65 million visitors a year who inject more than one billion dollars into the local economy....
    , Canada

Sources