Title: Time in the United States
Content: Eastern Time Zone (Zone R), which comprises roughly the states on the Atlantic coast and the eastern two thirds of the Ohio Valley. ; Central Time Zone (Zone S), which comprises roughly the Gulf Coast, Mississippi Valley, and most of the Great Plains. ; Mountain Time Zone (Zone T), which comprises roughly the states and portions of states that include the Rocky Mountains and the western quarter of the Great Plains. ; Pacific Time Zone (Zone U), which comprises roughly the states on the Pacific coast, plus Nevada and the Idaho Panhandle. From east to west, the four time zones of the contiguous United States are: 
Title: Time in the United States
Content:  Time in the United States, by law, is divided into nine standard time zones covering the states, territories and other US possessions, with most of the United States observing daylight saving time (DST) for approximately the spring, summer, and fall months. The time zone boundaries and DST observance are regulated by the Department of Transportation. Official and highly precise timekeeping services (clocks) are provided by two federal agencies: the National Institute of Standards and Technology (NIST) (an agency of the Department of Commerce); and the United States Naval Observatory (USNO). The clocks run by these services are kept synchronized with each other as well as with those of other international timekeeping organizations. It is the combination of the time zone and daylight saving rules, along with the timekeeping services, which determines the legal civil time for any U.S. location at any moment.
Title: Time in the United States
Content:  Standard time zones in the United States and other regions are currently defined at the federal level by law 15 USC §260. The federal law also establishes the transition dates and times at which daylight saving time occurs, if observed. It is ultimately the authority of the secretary of transportation, in coordination with the states, to determine which regions will observe which of the standard time zones and if they will observe daylight saving time. As of August 9, 2007, the standard time zones are defined in terms of hourly offsets from UTC. Prior to this they were based upon the mean solar time at several meridians 15° apart west of Greenwich (GMT). Only the full-time zone names listed below are official; abbreviations are by common use conventions, and duplicated elsewhere in the world for different time zones. The United States and its surrounding areas use nine standard time zones. As defined by U.S. law they are:
Title: List of UTC time offsets
Content: 🇺🇸 United States ; American Samoa ; United States Minor Outlying Islands ; Jarvis Island ; Kingman Reef ; Midway Atoll ; Palmyra Atoll ; 🇳🇿 New Zealand ; Niue 
Title: List of regions of the United States
Content: UTC−12:00 (Baker Island, Howland Island) ; Samoa Time Zone (American Samoa, Jarvis Island, Kingman Reef, Midway Atoll, Palmyra Atoll) ; Hawaii–Aleutian Time Zone (Hawaii, Aleutian Islands (Alaska), Johnston Atoll) ; Alaska Time Zone (Alaska, excluding Aleutian Islands) ; Pacific Time Zone ; Arizona Time Zone (excluding the Navajo Nation) ; Mountain Time Zone (excluding most parts of Arizona) ; Central Time Zone ; Eastern Time Zone ; Atlantic Time Zone (Puerto Rico, U.S. Virgin Islands) ; Chamorro Time Zone (Guam, Northern Mariana Islands) ; Wake Island Time Zone (Wake Island) 
Title: Time in the United States
Content: Alaska Time Zone (UTC−09:00; Zone V), which comprises most of the state of Alaska. ; Hawaii–Aleutian Time Zone (no daylight saving in Hawaii, UTC−10:00; zone W), which includes Hawaii and most of the length of the Aleutian Islands chain (west of 169°30′W). 
Title: Outline of the United States
Content: The United States is: a megadiverse country Location (50 states): ; Northern Hemisphere and Western Hemisphere (except western Aleutian Islands) ; Americas ; North America ; Northern America ; Oceania ; Polynesia ; Time zones: ; Atlantic Standard Time (UTC-04), Atlantic Daylight Time (UTC-03) (Puerto Rico and the United States Virgin Islands) ; Eastern Standard Time (UTC-05), Eastern Daylight Time (UTC-04) ; Central Standard Time (UTC-06), Central Daylight Time (UTC-05) ; Mountain Standard Time (UTC-07), Mountain Daylight Time (UTC-06) ; Pacific Standard Time (UTC-08), Pacific Daylight Time (UTC-07) ; Alaska Standard Time (UTC-09), Alaska Daylight Time (UTC-08) ; Hawaii-Aleutian Standard Time (UTC-10), Hawaii-Aleutian Daylight Time (UTC-09) ; Extreme points of the United States: ; North: Point Barrow, Alaska 71.3875°N, -156.48111°W ; South: Ka Lae, Island of Hawai'i, Hawai'i (18.91083°N, -155.68111°W) ; 
Title: Effects of time zones on North American broadcasting
Content:  The scheduling of television programming in North America (namely the United States, Canada, and Mexico) must cope with different time zones. The United States (excluding territories) has six time zones (Hawaii–Aleutian, Alaska, Pacific, Mountain, Central and Eastern), with further variation in the observance of daylight saving time. Canada also has about six time zones (Pacific, Mountain, Central, Eastern, Atlantic and Newfoundland). Mexico has four time zones (Pacific, Mountain, Central, and Eastern). This requires broadcast and pay television networks in each country to shift programs in time to show them in different regions.
Title: List of UTC time offsets
Content: 🇧🇸 Bahamas ; 🇧🇷 Brazil ; Acre ; Amazonas (13 western municipalities, approximately marked by a line between Tabatinga and Porto Acre) ; 🇨🇦 Canada (Eastern Time Zone) ; Nunavut ; East of 85th meridian west, and Southampton Island and adjoining islands ; Ontario ; East of 90° West ; Quebec ; Most of province except easternmost area ; 🇨🇴 Colombia ; 🇨🇺 Cuba ; 🇪🇨 Ecuador (except Galápagos Islands) ; 🇭🇹 Haiti ; 🇯🇲 Jamaica ; 🇲🇽 Mexico ; Quintana Roo ; 🇵🇦 Panama ; 🇵🇪 Peru ; 🇬🇧 United Kingdom ; Cayman Islands ; Turks and Caicos Islands ; 🇺🇸 United States (Eastern Time Zone) ; Delaware ; District of Columbia ; Florida ; Entire state except the counties of Bay, Calhoun, Escambia, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and Washington, and northern Gulf county (panhandle) 
Title: Daylight saving time in the United States
Content:  Daylight saving time in the United States is the practice of setting the clock forward by one hour when there is longer daylight during the day, so that evenings have more daylight and mornings have less. Most areas of the United States observe daylight saving time (DST), the exceptions being Arizona (except for the Navajo, who do observe daylight saving time on tribal lands), Hawaii, and the overseas territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the United States Virgin Islands. The Uniform Time Act of 1966 established the system of uniform daylight saving time throughout the US. In the U.S., daylight saving time 

Question: where are the timezones in the usa?
Answer: Pacific Time Zone.