U.S. time guide

United States Time Zones

Explore each U.S. time zone, the states or territories it covers, its standard and daylight offsets, and the location identifiers used by modern software.

Find the time zone for an address

Offsets can change seasonally

Areas that observe daylight saving time use a different UTC offset and abbreviation for part of the year. The individual guides show both values where they apply.

State borders and time-zone borders differ

A state can fall entirely within one zone or be divided between two zones. Use the linked state coverage guides for the important boundary details.

Browse all state guides

Time-zone guides

Choose a zone for state or territory coverage, offsets, abbreviations, and DST details.

Alaska

Alaska Time

Alaska Time covers Alaska except the Aleutian Islands west of 169 degrees 30 minutes west longitude. It is UTC-09:00 in standard time and UTC-08:00 in daylight time.UTC-09:00 · AKST · AKDTView details Atlantic

Atlantic Time

Atlantic Time is one of the nine federal U.S. time zones. Within populated U.S. territory it covers Puerto Rico and the U.S. Virgin Islands at UTC-04:00 year-round.UTC-04:00 · ASTView details Central

Central Time

Central Time covers a broad north-to-south band of the United States. It is UTC-06:00 in standard time and UTC-05:00 during daylight saving time.UTC-06:00 · CST · CDTView details Chamorro

Chamorro Time

Chamorro Time is UTC+10:00 year-round in Guam and the Northern Mariana Islands.UTC+10:00 · ChSTView details Eastern

Eastern Time

Eastern Time covers the eastern United States. It is UTC-05:00 in standard time and UTC-04:00 during daylight saving time.UTC-05:00 · EST · EDTView details Hawaii-Aleutian

Hawaii-Aleutian Time

Hawaii-Aleutian Time covers all of Hawaii and the Aleutian Islands west of 169 degrees 30 minutes west longitude. Its standard offset is UTC-10:00, but daylight-saving practice differs between Hawaii and Alaska.UTC-10:00 · HST · HDTView details Mountain

Mountain Time

Mountain Time covers much of the interior West. Its normal offsets are UTC-07:00 in standard time and UTC-06:00 in daylight time, with the important Arizona exception.UTC-07:00 · MST · MDTView details Pacific

Pacific Time

Pacific Time covers the West Coast and adjoining areas. It is UTC-08:00 in standard time and UTC-07:00 during daylight saving time.UTC-08:00 · PST · PDTView details Samoa

Samoa Time

Samoa Time is UTC-11:00 year-round in American Samoa. The federal zone is defined geographically in 49 CFR § 71.13.UTC-11:00 · SSTView details