US Time Zones Explained (Complete Guide)

The United States has 6 time zones. Here's a complete guide to every US time zone — which states are in each one, how they work, and answers to the most common questions.

Featured Answer

The United States has 6 time zones: Eastern, Central, Mountain, Pacific, Alaska, and Hawaii-Aleutian. The four mainland zones — Eastern, Central, Mountain, and Pacific — cover the contiguous 48 states. Each zone is one hour apart from the next, so the East Coast is always 3 hours ahead of the West Coast.

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How Many Time Zones Does the US Have?

The answer depends on how you count:

4 time zones — the four contiguous mainland zones (most people mean this)
6 time zones — including Alaska and Hawaii
9–10 time zones — including all US territories (Puerto Rico, Guam, American Samoa, etc.)

For everyday purposes, the answer is 6 official US time zones.

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The 6 US Time Zones Explained

1. Eastern Time (ET) — UTC-5 / UTC-4

Winter: EST (Eastern Standard Time) = UTC-5 Summer: EDT (Eastern Daylight Time) = UTC-4

Eastern Time is the most populous US time zone, home to about 53% of the US population. It drives American business hours, financial markets (NYSE opens at 9:30 AM ET), and TV schedules (prime time is 8–11 PM ET).

States fully in Eastern Time:

New York, New Jersey, Connecticut, Rhode Island, Massachusetts
Vermont, New Hampshire, Maine
Pennsylvania, Maryland, Delaware
Virginia, West Virginia, North Carolina, South Carolina, Georgia
Florida (most), Ohio, Michigan (most)

States partially in Eastern Time:

Indiana (most counties), Kentucky (eastern portion), Tennessee (eastern portion)

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2. Central Time (CT) — UTC-6 / UTC-5

Winter: CST (Central Standard Time) = UTC-6 Summer: CDT (Central Daylight Time) = UTC-5

Central Time covers the broad middle of the country. It is 1 hour behind Eastern and 1 hour ahead of Mountain year-round.

States fully in Central Time:

Illinois, Wisconsin, Minnesota, Iowa, Missouri
Oklahoma, Arkansas, Louisiana, Mississippi, Alabama
Kansas (most), Nebraska (most)

States mostly in Central Time:

Texas (all except El Paso area), Tennessee (most), Kentucky (western portion)
Indiana (small area), Michigan (Upper Peninsula, small area)
Florida (panhandle), North Dakota (most), South Dakota (most)

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3. Mountain Time (MT) — UTC-7 / UTC-6

Winter: MST (Mountain Standard Time) = UTC-7 Summer: MDT (Mountain Daylight Time) = UTC-6

Mountain Time is the least populous of the four mainland zones. It is 1 hour behind Central and 1 hour ahead of Pacific.

States fully in Mountain Time:

Colorado, Utah, Wyoming, Montana, New Mexico

States mostly in Mountain Time:

Arizona (all year on MST — no DST), Idaho (most), Nevada (small area)

States partially in Mountain Time:

Texas (El Paso area), Kansas (small western area), Nebraska (panhandle), North Dakota (small western area), South Dakota (western portion)

> The Arizona Exception: Arizona does not observe Daylight Saving Time. It stays on MST (UTC-7) year-round. In summer, Phoenix is on the same time as Los Angeles (PDT = UTC-7), not Denver (MDT = UTC-6). The Navajo Nation within Arizona is an exception — it does observe DST.

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4. Pacific Time (PT) — UTC-8 / UTC-7

Winter: PST (Pacific Standard Time) = UTC-8 Summer: PDT (Pacific Daylight Time) = UTC-7

Pacific Time covers the West Coast. It is 3 hours behind Eastern year-round.

States fully in Pacific Time:

California, Oregon, Washington

States mostly in Pacific Time:

Nevada (most), Idaho (northern portion)

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5. Alaska Time (AKT) — UTC-9 / UTC-8

Winter: AKST (Alaska Standard Time) = UTC-9 Summer: AKDT (Alaska Daylight Time) = UTC-8

Alaska observes DST. Most of Alaska uses this zone. The Aleutian Islands west of 169.5°W use Hawaii-Aleutian Time.

State: Alaska (most)

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6. Hawaii-Aleutian Time (HAT) — UTC-10

Year-round: HST (Hawaii Standard Time) = UTC-10

Hawaii does not observe Daylight Saving Time. It stays at UTC-10 all year.

State: Hawaii (all), plus the western Aleutian Islands of Alaska

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What State Has Two Time Zones?

Several US states are split between two time zones:

State	Primary Zone	Secondary Zone	Split Area
Texas	Central	Mountain	El Paso area
Kansas	Central	Mountain	Small western area
Nebraska	Central	Mountain	Western panhandle
North Dakota	Central	Mountain	Small western area
South Dakota	Central	Mountain	Western portion
Kentucky	Eastern	Central	Western counties
Tennessee	Central	Eastern	Eastern counties
Indiana	Eastern	Central	Small western area
Florida	Eastern	Central	Panhandle
Michigan	Eastern	Central	Upper Peninsula (small area)

The most well-known split-state is Indiana, which spent decades with counties individually choosing their time zone before standardizing to mostly Eastern Time in 2006.

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Is Texas in CST?

Yes — most of Texas is in Central Time (CST/CDT). This includes all major cities: Houston, Dallas, San Antonio, Austin, Fort Worth, and El Paso is the exception.

Texas Region	Time Zone	Winter	Summer
Most of Texas	Central	CST (UTC-6)	CDT (UTC-5)
El Paso area	Mountain	MST (UTC-7)	MDT (UTC-6)

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Is California in PST?

Yes — California is entirely in Pacific Time. The entire state uses PST in winter and PDT in summer. There are no split zones within California.

Season	California Time	UTC Offset
Winter (Nov–Mar)	PST	UTC-8
Summer (Mar–Nov)	PDT	UTC-7

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US Time Zone Quick Reference

Zone	Abbr (Winter)	UTC (Winter)	Abbr (Summer)	UTC (Summer)	Major Cities
Eastern	EST	UTC-5	EDT	UTC-4	New York, Miami, Atlanta
Central	CST	UTC-6	CDT	UTC-5	Chicago, Dallas, Houston
Mountain	MST	UTC-7	MDT	UTC-6	Denver, Phoenix, Salt Lake City
Pacific	PST	UTC-8	PDT	UTC-7	Los Angeles, Seattle, Las Vegas
Alaska	AKST	UTC-9	AKDT	UTC-8	Anchorage, Fairbanks
Hawaii	HST	UTC-10	HST	UTC-10	Honolulu, Hilo

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US Time Zone Relationships

The four mainland zones are always exactly 1 hour apart from each other:

Eastern = Central + 1 hour
Central = Mountain + 1 hour
Mountain = Pacific + 1 hour
Eastern = Pacific + 3 hours

This means when it is 9:00 AM in New York (ET), it is simultaneously:

8:00 AM in Chicago (CT)
7:00 AM in Denver (MT)
6:00 AM in Los Angeles (PT)
5:00 AM in Anchorage (AKT)
4:00 AM in Honolulu (HT)

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DST Switch Dates 2026

All US time zones (except Hawaii and most of Arizona) observe Daylight Saving Time on the same dates:

Event	2026 Date	What Happens
Spring forward	March 8, 2026	Clocks advance 1 hour at 2:00 AM
Fall back	November 1, 2026	Clocks fall back 1 hour at 2:00 AM