Time Zones in United States by State
Understanding US Time Zones
The United States spans six different time zones, a reflection of the country's vast geographical expanse from the Atlantic to the Pacific and beyond to Alaska and Hawaii. This diversity in time zones plays a crucial role in daily life, business operations, and travel across the nation.
Eastern Time (ET)
UTC-5 (Standard)
UTC-4 (Daylight)
Central Time (CT)
UTC-6 (Standard)
UTC-5 (Daylight)
Mountain Time (MT)
UTC-7 (Standard)
UTC-6 (Daylight)
Pacific Time (PT)
UTC-8 (Standard)
UTC-7 (Daylight)
Alaska Time (AKT)
UTC-9 (Standard)
UTC-8 (Daylight)
Hawaii-Aleutian (HST)
UTC-10 (Standard)
UTC-9 (Daylight)*
Quick Facts
- 13 states observe multiple time zones
- The Eastern Time Zone contains the most states (16 states entirely within it)
- Two states don't observe Daylight Saving Time (Arizona and Hawaii)
- The Navajo Nation observes DST despite being in Arizona
| State | Number of Time Zones | Time Zones | Details |
|---|---|---|---|
| Alabama | 1 | Central | |
| Alaska | 2 | Alaska, Hawaii-Aleutian |
Alaska Time Zone: Most of mainland Alaska
(99% of population)
Hawaii-Aleutian Time Zone: Aleutian Islands
(1% of population)
|
| Arizona | 1 | Mountain | Doesn't observe DST (except Navajo Nation) |
| Arkansas | 1 | Central | |
| California | 1 | Pacific | |
| Colorado | 1 | Mountain | |
| Connecticut | 1 | Eastern | |
| Delaware | 1 | Eastern | |
| Florida | 2 | Eastern, Central |
Eastern Time: Majority of the state
(92% of population)
|
| Georgia | 1 | Eastern | |
| Hawaii | 1 | Hawaii-Aleutian | Doesn't observe DST |
| Idaho | 2 | Pacific, Mountain |
Pacific Time: Northern Idaho (Idaho Panhandle)
(25% of population)
|
| Illinois | 1 | Central | |
| Indiana | 2 | Eastern, Central |
Eastern Time: Most of state, including Indianapolis
(82% of population)
Central Time: 12 counties in Northwest and Southwest
(18% of population)
|
| Iowa | 1 | Central | |
| Kansas | 2 | Central, Mountain |
Central Time: Most of the state
(99% of population)
Mountain Time: Four western counties
(1% of population)
|
| Kentucky | 2 | Eastern, Central |
Eastern Time: Eastern and central portions
(60% of population)
Central Time: Western portion
(40% of population)
|
| Louisiana | 1 | Central | |
| Maine | 1 | Eastern | |
| Maryland | 1 | Eastern | |
| Massachusetts | 1 | Eastern | |
| Michigan | 2 | Eastern, Central |
Eastern Time: Most of state, including both peninsulas
(97% of population)
Central Time: Four western Upper Peninsula counties
(3% of population)
|
| Minnesota | 1 | Central | |
| Mississippi | 1 | Central | |
| Missouri | 1 | Central | |
| Montana | 1 | Mountain | |
| Nebraska | 2 | Central, Mountain |
Central Time: Eastern portion, including Lincoln and Omaha
(87% of population)
Mountain Time: Western portion
(13% of population)
|
| Nevada | 1 | Pacific | |
| New Hampshire | 1 | Eastern | |
| New Jersey | 1 | Eastern | |
| New Mexico | 1 | Mountain | |
| New York | 1 | Eastern | |
| North Carolina | 1 | Eastern | |
| North Dakota | 2 | Central, Mountain |
Central Time: Most of the state
(94% of population)
Mountain Time: Southwest region
(6% of population)
|
| Ohio | 1 | Eastern | |
| Oklahoma | 1 | Central | |
| Oregon | 2 | Pacific, Mountain |
Pacific Time: Most of the state
(97% of population)
Mountain Time: Malheur County
(3% of population)
|
| Pennsylvania | 1 | Eastern | |
| Rhode Island | 1 | Eastern | |
| South Carolina | 1 | Eastern | |
| South Dakota | 2 | Central, Mountain |
Central Time: Eastern portion, including Pierre and Sioux Falls
(65% of population)
Mountain Time: Western portion
(35% of population)
|
| Tennessee | 2 | Eastern, Central |
Eastern Time: East Tennessee region
(37% of population)
|
| Texas | 2 | Central, Mountain |
Central Time: Most of the state
(96% of population)
|
| Utah | 1 | Mountain | |
| Vermont | 1 | Eastern | |
| Virginia | 1 | Eastern | |
| Washington | 1 | Pacific | |
| West Virginia | 1 | Eastern | |
| Wisconsin | 1 | Central | |
| Wyoming | 1 | Mountain |
Time Zone Distribution Overview
- Eastern Time Zone: Most populous zone, covering about 47% of the US population
- Central Time Zone: Second most populous, with approximately 33% of the population
- Mountain Time Zone: About 7% of the US population
- Pacific Time Zone: Approximately 17% of the population
- Alaska & Hawaii Time Zones: Less than 1% of the total US population
Did You Know?
Before the Standard Time Act of 1918, there were over 100 local time zones in the United States. Railroad companies were the driving force behind time zone standardization, as the lack of coordination made creating reliable train schedules nearly impossible.
Indiana only began observing Daylight Saving Time statewide in 2006. Before then, the state had a complex history of time zone observance, with different counties following different practices.
The state of Alaska spans nearly as many geographical time zones as the entire contiguous United States, but for practical purposes, most of the state uses a single time zone.
References and Further Reading
- U.S. Department of Transportation (DOT) - Official time zone boundaries
- National Institute of Standards and Technology (NIST) - Time and frequency services