There are 9 standard time zones in the U.S. officially defined by federal law. The entire 50 states and the District of Columbia have 6 main time zones. The other 3 time zones, namely; UTC-04:00 Atlantic Time Zone, UTC-11:00 Samoa Time Zone and UTC+10:00 Chamorro Time Zone, are used in the insular areas of the U.S, outside of the states.
Nowadays, 48 of the U.S states use Daylight Saving Time (DST) in the summer period, the exceptions are Arizona, where most of the territories do not change to DST (since 1967), and the entire Hawaii, which has never observed the summertime. All insular territories like Puerto Rico, US Virgin Islands, American Samoa, Guam and the Northern Mariana Islands have no DST.
Time zones in the United States
Here are the 9 time zones in the Unites States of America.
- UTC-05:00 Eastern Time Zone, the most populous in the USA, includes the District of Columbia with the capital city of Washington and 23 states wholly or partially located within this zone. De facto the Eastern Time often is used as the USA official time.
- UTC-06:00 Central Time Zone, the largest one by area, encompasses 20 states, but only 10 of them are located entirely within zone’s boundaries, all remaining states have some exceptions.
- UTC-07:00 Mountain Time Zone includes 14 states, only 6 of them are wholly in this zone, all the others use the Mountain Time in some parts of their territories.
- UTC-08:00 Pacific Time Zone covers 6 states – the entire states of California and Washington, most of Nevada and Oregon with some exceptions, the Metlakatla Indian Community in Alaska, and some northern parts of Idaho.
- UTC-09:00 Alaska Time Zone, as clearly observed in its name, includes the most of the territory of Alaska.
- UTC-10:00 Hawaii-Aleutian Time Zone covers Hawaii and western part of the Aleutian Islands belonging to Alaska.
- UTC-04:00 Atlantic Time Zone comprises the Puerto Rico and the United States Virgin Islands in the Caribbean.
- UTC-11:00 Samoa Time Zone embraces the American Samoa islands in the South Pacific.
- UTC+10:00 Chamorro Time Zone comprises Guam and the Northern Mariana Islands, located in the northwestern part of the Pacific Ocean.
Time zones for the United States Minor Outlying Islands
Some overseas territories governed by the USA in the Pacific and the Caribbean, so called the United States Minor Outlying Islands have the following standard time zones not specified in the federal law, and these areas don’t change to DST.
- UTC+12: Wake Island.
- UTC-12: Baker Island and Howland Island.
- UTC-11: Jarvis Island, Midway Atoll, Palmyra Atoll, and Kingman Reef.
- UTC-10: Johnston Atoll.
- UTC-05: Navassa Island.
Time zones for the states of the United States of America
Here are the U.S. states with their standard time zones and DST.
| State | Capital and the largest city | UTC time offset | DST |
| A | |||
| Alabama (AL) | Montgomery, Birmingham | -06:00 | -05:00 |
| Alaska (AK), most of | Juneau, Anchorage | -09:00 | -08:00 |
| Alaska (AK), small part | Adak, Unalaska | -10:00 | -09:00 |
| Alaska (AK), small part | Metlakatla Indian Community | -08:00 | none |
| Arizona (AZ), most of | Phoenix | -07:00 | none |
| Arizona (AZ), small part | Window Rock | -07:00 | -06:00 |
| Arkansas (AR) | Little Rock | -06:00 | -05:00 |
| C | |||
| California (CA) | Sacramento, Los Angeles | -08:00 | -07:00 |
| Colorado (CO) | Denver | -07:00 | -06:00 |
| Connecticut (CT) | Hartford, Bridgeport | -05:00 | -04:00 |
| D | |||
| Delaware (DE) | Dover, Wilmington | -05:00 | -04:00 |
| District of Columbia (DC) | Washington, D.C. (capital of USA) | -05:00 | -04:00 |
| F | |||
| Florida (FL), most of | Tallahassee, Jacksonville | -05:00 | -04:00 |
| Florida (FL), small part | Pensacola | -06:00 | -05:00 |
| G | |||
| Georgia (GA) | Atlanta | -05:00 | -04:00 |
| H | |||
| Hawaii (HI) | Honolulu | -10:00 | none |
| I | |||
| Idaho (ID), most of | Boise | -07:00 | -06:00 |
| Idaho (ID), small part | Coeur d’Alene | -08:00 | -07:00 |
| Illinois (IL) | Springfield, Chicago | -06:00 | -05:00 |
| Indiana (IN), most of | Indianapolis | -05:00 | -04:00 |
| Indiana (IN), small part | Gary, Evansville | -06:00 | -05:00 |
| Iowa (IA) | Des Moines | -06:00 | -05:00 |
| K | |||
| Kansas (KS), most of | Topeka, Wichita | -06:00 | -05:00 |
| Kansas (KS), small part | Goodland | -07:00 | -06:00 |
| Kentucky (KY), most of | Frankfort, Louisville | -05:00 | -04:00 |
| Kentucky (KY), small part | Bowling Green | -06:00 | -05:00 |
| L | |||
| Louisiana (LA) | Baton Rouge, New Orleans | -06:00 | -05:00 |
| M | |||
| Maine (ME) | Augusta, Portland | -05:00 | -04:00 |
| Maryland (MD) | Annapolis, Baltimore | -05:00 | -04:00 |
| Massachusetts (MA) | Boston | -05:00 | -04:00 |
| Michigan (MI), most of | Lansing, Detroit | -05:00 | -04:00 |
| Michigan (MI), small part | Iron Mountain | -06:00 | -05:00 |
| Minnesota (MN) | St. Paul, Minneapolis | -06:00 | -05:00 |
| Mississippi (MS) | Jackson | -06:00 | -05:00 |
| Missouri (MO) | Jefferson City, Kansas City | -06:00 | -05:00 |
| Montana (MT) | Helena, Billings | -07:00 | -06:00 |
| N | |||
| Nebraska (NE), most of | Lincoln, Omaha | -06:00 | -05:00 |
| Nebraska (NE), small part | Scottsbluff, Chadron | -07:00 | -06:00 |
| Nevada (NV), most of | Carson City, Las Vegas | -08:00 | -07:00 |
| Nevada (NV), small part | West Wendover | -07:00 | -06:00 |
| New Hampshire (NH) | Concord, Manchester | -05:00 | -04:00 |
| New Jersey (NJ) | Trenton, Newark | -05:00 | -04:00 |
| New Mexico (NM) | Santa Fe, Albuquerque | -07:00 | -06:00 |
| New York (NY) | Albany, New York City | -05:00 | -04:00 |
| North Carolina (NC) | Raleigh, Charlotte | -05:00 | -04:00 |
| North Dakota (ND), most of | Bismarck, Fargo | -06:00 | -05:00 |
| North Dakota (ND), small part | Dickinson | -07:00 | -06:00 |
| O | |||
| Ohio (OH) | Columbus | -05:00 | -04:00 |
| Oklahoma (OK) | Oklahoma City | -06:00 | -05:00 |
| Oregon (OR), most of | Salem, Portland | -08:00 | -07:00 |
| Oregon (OR), small part | Ontario | -07:00 | -06:00 |
| P | |||
| Pennsylvania (PA) | Harrisburg, Philadelphia | -05:00 | -04:00 |
| R | |||
| Rhode Island (RI) | Providence | -05:00 | -04:00 |
| S | |||
| South Carolina (SC) | Columbia, Charleston | -05:00 | -04:00 |
| South Dakota (SD), most of | Pierre, Sioux Falls | -06:00 | -05:00 |
| South Dakota (SD), small part | Rapid City | -07:00 | -06:00 |
| T | |||
| Tennessee (TN), most of | Nashville | -06:00 | -05:00 |
| Tennessee (TN), small part | Knoxville, Chattanooga | -05:00 | -04:00 |
| Texas (TX), most of | Austin, Houston | -06:00 | -05:00 |
| Texas (TX), small part | El Paso | -07:00 | -06:00 |
| U | |||
| Utah (UT) | Salt Lake City | -07:00 | -06:00 |
| V | |||
| Vermont (VT) | Montpelier, Burlington | -05:00 | -04:00 |
| Virginia (VA) | Richmond, Virginia Beach | -05:00 | -04:00 |
| W | |||
| Washington (WA) | Olympia, Seattle | -08:00 | -07:00 |
| West Virginia (WV) | Charleston | -05:00 | -04:00 |
| Wisconsin (WI) | Madison, Milwaukee | -06:00 | -05:00 |
| Wyoming (WY) | Cheyenne | -07:00 | -06:00 |
