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). Canada follows United States daylight time. In 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, one hour behind the Mountain Time Zone and three hours behind the Eastern Time Zone.

United States

main: Time in the United States In the United States, the states of Washington and California are located entirely within the Pacific Time Zone. 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. The exact specification for the location of time zones and the dividing line between zones is set forth in the Code of Federal Regulations at 49 CFR 71.The specification for the Pacific Time Zone as it pertains to the United States is set forth at 49 CFR 71.10, and is listed in Text and pdf formats.
The boundary between Pacific and Mountain in the United States is set forth at 49 CFR 71.9, and is listed in text and pdf formats.

Canada

main: Time in Canada In Canada, Pacific Time includes almost all of the province of British Columbia (except for the Highway 95 corridor and portions around Fort St. John, Dawson Creek and Creston), all of the Yukon Territory and Tungsten, Northwest Territories.

Mexico

main: Time in Mexico In Mexico, the state of Baja California is wholly within and the only part of Mexico in the Northwest 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.