Pacific Standard Time
The clock time in this zone is based on the mean solar time of the 120th degree meridian west of the Greenwich Observatory. During daylight saving time, its time offset is UTC-7.
In the United States and Canada, this time zone is generically called Pacific Time (PT).
Specifically, it is Pacific Standard Time (PST) when observing standard time (Winter), and Pacific Daylight Time (PDT) when observing daylight saving time (Summer). In Mexico the UTC-8 time zone is known as the Northwest Zone (Zona Noroeste), which formerly was synchronized with the U.S.
Nearly all of Nevada, except for the towns of West Wendover and Jackpot, is on Pacific Time. Additionally, all of Oregon except for the greater part of Malheur County and the northern part of Idaho (the Idaho Panhandle) are also in the zone.
Also the westernmost of the Revillagigedo Islands (Colima), Clarion Island uses the Northwest Zone.
Daylight time
During summer months, Sonora and most of 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, Oregon, Nevada, California, Baja California, British Columbia, and Yukon Territory combined.
Over 1,000,000 residents
Los Angeles, California, USA
San Diego, California, USA
Tijuana, Baja California, Mexico
Over 700,000 residents
San Francisco, California, USA
San Jose, California, USA
Mexicali, Baja California, Mexico
Over 400,000 residents
Ensenada, Baja California, Mexico
Fresno, California, USA
Las Vegas, Nevada, USA
Long Beach, California, USA
Oakland, California, USA
Portland, Oregon, USA
Seattle, Washington, USA
Sacramento, California, USA
Vancouver, British Columbia, Canada
Over 200,000 residents
Anaheim, California, USA
Bakersfield, California, USA
Fremont, California, USA
Henderson, Nevada, USA
Irvine, California, USA
Modesto, California, USA
Reno, Nevada, USA
Riverside, California, USA
Santa Ana, California, USA
Spokane, Washington, USA
Stockton, California, USA
Tacoma, Washington, USA
Victoria, British Columbia, Canada
.