US time zones by state: complete guide to all 50 states

The four main US time zones

The continental United States is divided into four standard time zones, established by the Standard Time Act of 1918 and maintained by the Department of Transportation. From east to west, each zone is separated by one hour.

Eastern Time (ET) — UTC-5 standard, UTC-4 daylight saving. This is the most populated time zone in the US, covering roughly 47% of the population. Major cities include New York, Washington D.C., Miami, Atlanta, Boston, Philadelphia, and Detroit.

Central Time (CT) — UTC-6 standard, UTC-5 daylight saving. The second most populated zone, covering the heartland. Major cities include Chicago, Dallas, Houston, Minneapolis, New Orleans, Nashville, and San Antonio.

Mountain Time (MT) — UTC-7 standard, UTC-6 daylight saving. The least populated of the four main zones. Major cities include Denver, Phoenix, Salt Lake City, Albuquerque, Las Vegas (Nevada is Pacific, but Las Vegas is commonly grouped culturally with Mountain cities), and El Paso.

Pacific Time (PT) — UTC-8 standard, UTC-7 daylight saving. Covers the West Coast. Major cities include Los Angeles, San Francisco, Seattle, Portland, San Diego, and Sacramento.

Beyond the continental US, Alaska Time (AKT) is UTC-9 and Hawaii-Aleutian Time (HST) is UTC-10. You can see all of these on the time zone map or check current times on the world clock.

Every US state and its time zone

Eastern Time states

The following states are entirely in the Eastern Time zone:

• Connecticut
• Delaware
• Georgia
• Maine
• Maryland
• Massachusetts
• New Hampshire
• New Jersey
• New York
• North Carolina
• Ohio
• Pennsylvania
• Rhode Island
• South Carolina
• Vermont
• Virginia
• Washington D.C. (federal district)
• West Virginia

Central Time states

The following states are entirely in the Central Time zone:

• Alabama
• Arkansas
• Illinois
• Iowa
• Louisiana
• Minnesota
• Mississippi
• Missouri
• Oklahoma
• Wisconsin

Mountain Time states

The following states are entirely in the Mountain Time zone:

• Arizona (does not observe DST — see below)
• Colorado
• Montana
• New Mexico
• Utah
• Wyoming

Pacific Time states

The following states are entirely in the Pacific Time zone:

• California
• Nevada
• Washington

Alaska and Hawaii

• Alaska uses Alaska Standard Time (AKST, UTC-9). The westernmost Aleutian Islands use Hawaii-Aleutian Time (HST, UTC-10).
• Hawaii uses Hawaii-Aleutian Standard Time (HST, UTC-10) and does not observe daylight saving time.

States that span two time zones

Thirteen US states are split between two time zones. This often creates confusion for residents near the border and for anyone scheduling calls or meetings with people in these states. Here is the complete list.

Florida — Eastern and Central

Most of Florida is in the Eastern Time zone. The Florida Panhandle — the western portion of the state including Pensacola, Panama City, and areas west of the Apalachicola River — is in the Central Time zone. If you are calling someone in Jacksonville or Miami, use Eastern. If they are in Pensacola, use Central.

Indiana — Eastern and Central

Indiana was famously complicated for decades, with different counties choosing different zones and some not observing DST. Since 2006, all of Indiana observes daylight saving time. Most of the state is in Eastern Time. However, 12 counties in the northwest corner (near Chicago) and 6 counties in the southwest corner (near Evansville) observe Central Time.

Michigan — Eastern and Central

The vast majority of Michigan is in the Eastern Time zone, including Detroit and Grand Rapids. Four counties in the Upper Peninsula that border Wisconsin — Gogebic, Iron, Dickinson, and Menominee — are in the Central Time zone.

Tennessee — Eastern and Central

Tennessee is split roughly in half. The eastern portion, including Knoxville and Chattanooga, is in Eastern Time. The western portion, including Nashville and Memphis, is in Central Time. The dividing line runs roughly along the Cumberland Plateau.

Kentucky — Eastern and Central

Like Tennessee, Kentucky is split. The eastern part of the state, including Lexington, is in Eastern Time. The western part, including Bowling Green and Paducah, is in Central Time. Louisville, the largest city, is in the Eastern Time zone.

North Dakota — Central and Mountain

Most of North Dakota is in the Central Time zone. The southwestern corner of the state, along the Montana border, is in Mountain Time.

South Dakota — Central and Mountain

The eastern half of South Dakota, including Sioux Falls, is in Central Time. The western half, including Rapid City and the Black Hills, is in Mountain Time. The dividing line runs roughly along the Missouri River.

Nebraska — Central and Mountain

Most of Nebraska, including Omaha and Lincoln, is in the Central Time zone. The western panhandle, including Scottsbluff, is in Mountain Time.

Kansas — Central and Mountain

Nearly all of Kansas is in the Central Time zone. A small strip of counties in the far western part of the state (Greeley, Hamilton, Sherman, and Wallace counties) observe Mountain Time.

Texas — Central and Mountain

The vast majority of Texas is in the Central Time zone, including Dallas, Houston, Austin, and San Antonio. The far western tip, including El Paso and Hudspeth County, is in the Mountain Time zone.

Oregon — Pacific and Mountain

Most of Oregon, including Portland, Salem, and Eugene, is in the Pacific Time zone. The eastern part of the state — roughly the portion east of the Cascade Range in Malheur County — observes Mountain Time.

Idaho — Pacific and Mountain

The southern part of Idaho, including Boise, is in the Mountain Time zone. The northern panhandle, including Coeur d'Alene and Moscow, is in the Pacific Time zone.

Alaska — Alaska Time and Hawaii-Aleutian Time

Most of Alaska uses Alaska Standard Time (UTC-9). The far western Aleutian Islands, including Adak, use Hawaii-Aleutian Standard Time (UTC-10).

Use the time zone map to see exactly where these boundaries fall, or use the time zone converter to check the current time in any location.

DST exceptions: Arizona and Hawaii

Two states do not observe daylight saving time, making their time zone relationships shift depending on the season.

Arizona

Arizona stays on Mountain Standard Time (UTC-7) year-round. During winter, Arizona matches the rest of the Mountain zone. During summer, when Mountain Time states shift to MDT (UTC-6), Arizona remains at UTC-7. This means Arizona is effectively aligned with Pacific Daylight Time during summer.

The one exception is the Navajo Nation, which spans parts of Arizona, Utah, and New Mexico. The Navajo Nation does observe daylight saving time to maintain consistency across its territory. However, the Hopi Reservation, which is surrounded by the Navajo Nation within Arizona, does not observe DST. This creates the unusual situation of a DST island within a non-DST state within a DST nation.

Hawaii

Hawaii uses Hawaii-Aleutian Standard Time (UTC-10) year-round. Because Hawaii never changes its clocks, the time difference between Hawaii and the mainland varies by season. During winter, Hawaii is 2 hours behind the Pacific Coast and 5 hours behind the East Coast. During summer, the gap increases to 3 hours behind Pacific and 6 hours behind Eastern.

A brief history of US time zones

Before 1883, there were no standardized time zones in the United States. Every city set its own local mean time based on the sun's position. Railroad companies maintained dozens of different time standards, leading to dangerous scheduling conflicts and public confusion.

On November 18, 1883, the railroads adopted four standard time zones for the continental US, and most cities quickly followed. This was a private industry solution — the federal government did not officially adopt standard time zones until the Standard Time Act of 1918, which also introduced daylight saving time during World War I.

The Uniform Time Act of 1966 standardized the dates for DST transitions across the country but allowed states to opt out entirely. Arizona opted out in 1968, and Hawaii, which had briefly observed DST during wartime, chose not to adopt it when statehood came in 1959.

The boundaries between time zones are set by the Department of Transportation, not by geographic longitude. This is why some state boundaries do not align with the "neat" 15-degree zones you would expect on a map. Political, economic, and social factors all influence where the lines are drawn.

Frequently asked questions

How many time zones does the US have?
The US has six standard time zones: Eastern, Central, Mountain, Pacific, Alaska, and Hawaii-Aleutian. US territories add more — Samoa (UTC-11), Guam and the Northern Mariana Islands (UTC+10), Puerto Rico and the US Virgin Islands (UTC-4), and several Pacific islands.

What time zone is New York in?
New York is in the Eastern Time zone — EST (UTC-5) during standard time and EDT (UTC-4) during daylight saving time.

What time zone is California in?
California is in the Pacific Time zone — PST (UTC-8) during standard time and PDT (UTC-7) during daylight saving time. The entire state is in one zone.

Which state is in the most time zones?
Alaska technically spans two time zones (Alaska Time and Hawaii-Aleutian Time in the far western Aleutian Islands). Among continental states, no single state spans more than two zones. Tennessee, Kentucky, and several others are split between two zones.

Why does Arizona not observe daylight saving time?
Arizona opted out of DST in 1968 because the additional hour of evening sunlight during summer means even higher temperatures in an already extremely hot climate. Residents preferred the sun to set earlier. The Navajo Nation within Arizona does observe DST to stay synchronized with its territory in Utah and New Mexico.

Which states have tried to change their time zone or DST status?
Many states have passed legislation in recent years. Florida passed the "Sunshine Protection Act" in 2018 to adopt permanent DST. Washington, Oregon, and California have also passed or proposed similar measures. However, these changes require federal approval under the Uniform Time Act, and Congress has not yet acted. You can track current DST status and upcoming changes on our daylight saving time page.

What is the easiest way to find my time zone?
Use the time zone map on Timerjoy. It shows all US time zone boundaries and automatically detects your current location. For live clocks across all zones, check the world clock.