Pacific Time Zone

The Pacific Time Zone observes standard time by subtracting eight hours from Coordinated Universal Time (UTC−8). The standard time in this zone is based on the mean solar time of the 120th meridian west of the Greenwich Observatory. During daylight saving time, its time offset is UTC−7 and is thus based on the mean solar time of the 105th meridian west of the Greenwich Observatory.

In the United States and Canada, this time zone is generically called the Pacific Time Zone (PT). Specifically, it uses Pacific Standard Time (PST) when observing standard time (late autumn to early spring), and Pacific Daylight Time (PDT) when observing daylight saving time (early spring to late autumn). Most of Canada uses daylight saving time. In Mexico the UTC−8 time zone is known as the Northwest Zone, which is synchronized with the U.S. PDT daylight saving schedule.

The largest city in the Pacific Time Zone is Los Angeles, California; the city's metropolitan area is the largest in the zone.

The zone is one hour ahead of the Alaska Time Zone, one hour behind the Mountain Time Zone, two hours behind the Central Time Zone, and three hours behind the Eastern Time Zone.

United States

The following states and/or areas are part of the Pacific Time Zone:

• California
• Washington
• Oregon – all, except for most of Malheur County, on the 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).
• Nevada
• Idaho Panhandle – the northern half of Idaho, north of the Salmon River.

The town of Hyder, Alaska, is officially in the Alaska Time Zone. However, most of the town observes the Pacific Time because of strong connections with nearby Stewart, British Columbia, which is in the Pacific Time Zone. The United States Post Office in Hyder strictly adheres to Alaska Time.

Canada

In Canada, the Pacific Time Zone includes most of British Columbia (except for the Highway 95 corridor and portions around Tumbler Ridge, Fort St. John, Dawson Creek, Golden and Creston), all of Yukon and Tungsten, Northwest Territories.

Mexico

In Mexico, the state of Baja California lies completely within the Pacific Time Zone. This does not include the state of Baja California Sur, which is south of Baja California.

Daylight time

Through 2006, the local time (PST, UTC−8) changed to daylight time (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 U.S. 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. The Canadian provinces and territories that use daylight time each adopted these dates between October 2005 and February 2007. 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.

See also

• Effects of time zones on North American broadcasting

References

Sources

• The official U.S. time for the Pacific Time Zone
• Official times across Canada
• World time zone map
• U.S. time zone map
• History of U.S. time zones and UTC conversion
• Canada time zone map
• Time zones for major world cities