Time Zones in the United States: Complete Guide

The United States spans an enormous geographic area and uses multiple time zones. Understanding US time zones is essential for domestic travel, business communication, and coordination with American colleagues.

How Many Time Zones Does the US Have?

The United States uses six standard time zones for its 50 states, plus additional zones for its territories:

Eastern Time (ET) — UTC-5 (EST) / UTC-4 (EDT)

Central Time (CT) — UTC-6 (CST) / UTC-5 (CDT)

Mountain Time (MT) — UTC-7 (MST) / UTC-6 (MDT)

Pacific Time (PT) — UTC-8 (PST) / UTC-7 (PDT)

Alaska Time (AKT) — UTC-9 (AKST) / UTC-8 (AKDT)

Hawaii-Aleutian Time (HST) — UTC-10 (HST) / UTC-9 (HDT)

Additionally, territories use:

Atlantic Time: Puerto Rico, US Virgin Islands (UTC-4)

Chamorro Time: Guam, Northern Mariana Islands (UTC+10)

Samoa Time: American Samoa (UTC-11)

States and Their Time Zones

Many states are split across two time zones. Here's a quick reference:

Eastern Time (ET)

New York, New Jersey, Pennsylvania, Delaware, Maryland, Washington D.C., Virginia, West Virginia, Ohio, Michigan (most), Indiana (most), Kentucky (eastern half), Tennessee (eastern third), Florida (panhandle), Georgia, Carolina, Vermont, New Hampshire, Maine, Massachusetts, Rhode Island, Connecticut

Central Time (CT)

Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Iowa, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Wisconsin, Illinois, Tennessee (central/western), Kentucky (western half), Florida (northwest), Michigan (western edge), Indiana (northwest)

Mountain Time (MT)

Montana, Wyoming, Colorado, New Mexico, Arizona (Navajo Nation only), Utah, Idaho (southern), North Dakota (southwest corner), South Dakota (western half), Nebraska (western panhandle), Kansas (western edge), Oregon (small eastern part), Texas (western tip, El Paso)

Pacific Time (PT)

California, Washington, Oregon (most), Nevada, Idaho (northern)

Alaska Time

All of Alaska except the western Aleutian Islands

Hawaii-Aleutian Time

Hawaii, western Aleutian Islands (Alaska)

The Arizona Exception

Arizona is unique — most of the state does not observe Daylight Saving Time and stays on Mountain Standard Time (UTC-7) year-round. However, the Navajo Nation in northeastern Arizona does observe DST. This creates a bizarre situation where driving through Arizona during summer might require changing your clock multiple times.

Major Cities and Their Time Zones

CityTime ZoneUTC Offset (Winter) ------------------------------------ New YorkETUTC-5 ChicagoCTUTC-6 DenverMTUTC-7 Los AngelesPTUTC-8 AnchorageAKTUTC-9 HonoluluHSTUTC-10

Tips for Working with US Time Zones

New York is 3 hours ahead of Los Angeles. A 9 AM meeting in New York is 6 AM in Los Angeles — too early for the West Coast.

The best overlap for US-wide meetings is 12-3 PM ET (9 AM-12 PM PT). This works for all US zones including Hawaii (7-10 AM HST).

Remember DST changes. Most US clocks spring forward in March and fall back in November, shifting the UTC offset by one hour.

Dont forget about Arizona. If you have colleagues in Phoenix, they dont change clocks for DST (except on the Navajo Nation).

Use timezone abbreviations carefully. EST specifically means winter time (UTC-5), while ET is the general term that could be EST or EDT.

The US time zone system may seem complex, but with the right tools and understanding, navigating it becomes straightforward. Use WorldTimezone to quickly check any US city and its current timezone.