US Time Zone Converter: All 10 American Time Zones Live, EST PST CST MST Alaska Hawaii Puerto Rico Guam Samoa

From east to west: (1) Atlantic Standard Time / AST (UTC-4, Puerto Rico and US Virgin Islands, no DST); (2) Eastern Time / ET (UTC-5 standard / UTC-4 DST); (3) Central Time / CT (UTC-6 standard / UTC-5 DST); (4) Mountain Time / MT (UTC-7 standard / UTC-6 DST); (5) Arizona / MST (UTC-7 always, no DST); (6) Pacific Time / PT (UTC-8 standard / UTC-7 DST); (7) Alaska Time / AKT (UTC-9 standard / UTC-8 DST); (8) Hawaii / HST (UTC-10 always, no DST); (9) Samoa / SST (UTC-11 always, no DST). Guam (UTC+10) is technically west of the continental US but east of UTC via the International Date Line.

Eastern Time covers 23 states plus DC: Connecticut, Delaware, Florida, Georgia, Indiana (most counties), Kentucky (most), Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee (eastern counties), Vermont, Virginia, West Virginia, and Washington DC. Indiana is split: most counties are ET, but some western counties near Illinois and Kentucky are Central Time. Tennessee has eastern counties on ET and western counties (Memphis area) on CT. The Eastern Time zone covers approximately 50% of the US population, making it the most populous zone.

No. Arizona (except the Navajo Nation) does not observe Daylight Saving Time. The state stays permanently on Mountain Standard Time (MST, UTC-7). Arizona’s legislature exempted the state from DST in 1968, one year after the federal Uniform Time Act of 1966 took effect, citing the state’s hot summer climate (adding an hour of daylight to already extreme afternoon heat was seen as counterproductive). The practical effect: Arizona is 3 hours behind Eastern Time in summer (when ET uses EDT, UTC-4) but only 2 hours behind in winter (when ET uses EST, UTC-5). Arizona equals Pacific Daylight Time (PDT) in summer and Mountain Standard Time (MST) in winter. The Navajo Nation, which occupies northeast Arizona, does observe DST (MDT), creating a DST boundary inside Arizona itself.

Eastern Standard Time (EST, UTC-5) and Pacific Standard Time (PST, UTC-8) are 3 hours apart. When it is noon EST, it is 9 AM PST. This 3-hour gap stays constant year-round because both zones observe DST simultaneously: they both shift to EDT (UTC-4) and PDT (UTC-7) in March, and both shift back in November, maintaining the same 3-hour difference. The gap only appears to change if you compare EST to PDT or EDT to PST, which can happen during the brief transition window when one zone has shifted and the other has not yet (usually a few weeks around March and November in some international comparisons).

Pacific Time covers five states (or portions of states): California (entirely), Nevada (most, except Jackpot area near Idaho border which is MT), Oregon (most; Malheur County is MT), Washington State (entirely), and the northern panhandle of Idaho (including Coeur d’Alene and Moscow). Pacific Time is UTC-8 in winter (PST) and UTC-7 in summer (PDT). Major cities in Pacific Time: Los Angeles, San Diego, San Francisco, Oakland, Sacramento, Seattle, Portland, Las Vegas, and Reno. The Pacific zone covers roughly 53 million people and is the second most populous US time zone after Eastern.

The US has nine standard time zones used across its states and territories: Eastern, Central, Mountain, Pacific, Alaska, Hawaii-Aleutian, Samoa (American Samoa), Atlantic (Puerto Rico/USVI), and Chamorro (Guam/CNMI). Arizona adds a tenth de facto zone because it uses MST year-round without DST, effectively operating independently of the Mountain Time zone during summer months. Including uninhabited territories and military installations, the US spans even more UTC offsets, but the 10 zones covered in this converter represent all inhabited US jurisdiction time zones.

Hawaii observes Hawaii-Aleutian Standard Time (HST), UTC-10, year-round. Hawaii has not observed Daylight Saving Time since 1947 (except during World War II), making it a fixed-offset zone. The gap between Hawaii and the US mainland varies by season: Hawaii is 5 hours behind Eastern Standard Time in winter (EST, UTC-5) and 6 hours behind Eastern Daylight Time in summer (EDT, UTC-4). Hawaii is 2 hours behind Pacific Standard Time in winter (PST, UTC-8) and 3 hours behind Pacific Daylight Time in summer (PDT, UTC-7). When scheduling between Hawaii and the mainland, the gap changes each March and November when mainland zones shift for DST while Hawaii stays fixed.

In 2025, Daylight Saving Time in the US begins at 2:00 AM on Sunday, March 9, 2025 (second Sunday in March). Clocks spring forward to 3:00 AM, losing one hour of sleep. DST ends at 2:00 AM on Sunday, November 2, 2025 (first Sunday in November). Clocks fall back to 1:00 AM, gaining one hour of sleep. These rules have been in effect since 2007 under the Energy Policy Act of 2005. Arizona (except Navajo Nation), Hawaii, Puerto Rico, Guam, and American Samoa do not observe DST and make no clock changes on these dates. Congress has periodically debated making DST permanent (the Sunshine Protection Act), but as of 2025 no change to federal law has been enacted.

Puerto Rico observes Atlantic Standard Time (AST), UTC-4, year-round without Daylight Saving Time. It shares this offset with the US Virgin Islands. In summer (when the US East Coast is on EDT, UTC-4), Puerto Rico is at the same time as New York, Miami, and Washington DC. In winter (when the East Coast is on EST, UTC-5), Puerto Rico is 1 hour ahead of Eastern Time. The US Virgin Islands (St. Thomas, St. John, St. Croix) also observe AST year-round. Puerto Rico’s time zone means it is always 3 hours ahead of Pacific Standard Time in winter and 3 hours ahead of Pacific Daylight Time in summer (since PR stays at UTC-4 while PT shifts between UTC-8 and UTC-7).

Eastern Standard Time (EST, UTC-5) is always 1 hour ahead of Central Standard Time (CST, UTC-6). To convert EST to CST, subtract 1 hour: 9 AM EST = 8 AM CST. 12 PM (noon) EST = 11 AM CST. 5 PM EST = 4 PM CST. This 1-hour gap stays constant year-round because both zones observe DST simultaneously: in summer, EDT (UTC-4) is still exactly 1 hour ahead of CDT (UTC-5). The ET-CT gap is one of the most consistent in the US time zone system.

Eastern Time (EST/EDT) is always exactly 1 hour ahead of Central Time (CST/CDT). EST = UTC-5, CST = UTC-6 in winter; EDT = UTC-4, CDT = UTC-5 in summer. The 1-hour difference is permanent regardless of DST, because both zones shift at exactly the same time on the same dates. When scheduling between New York and Chicago: 9 AM ET = 8 AM CT. 3 PM ET = 2 PM CT. 5 PM ET = 4 PM CT. This is the most commonly needed US time zone conversion for domestic business calls, since ET and CT together cover the majority of the US population and economy.

Most of Alaska observes Alaska Time (AKT), which is AKST (UTC-9) in winter and AKDT (UTC-8) in summer when DST is active. Alaska is 1 hour behind Pacific Time and 4 hours behind Eastern Time year-round (since both AK and ET observe DST simultaneously, the gap is constant). The Aleutian Islands west of 169 degrees 30 minutes west longitude (including Unalaska/Dutch Harbor and westward) observe Hawaii-Aleutian Time (HAST/HADT), putting them on the same base as Hawaii but with DST. Alaska’s DST start and end dates are the same as the continental US: second Sunday in March and first Sunday in November.

Most of Texas observes Central Time (CT): CST (UTC-6) in winter and CDT (UTC-5) in summer. Two exceptions: El Paso County and Hudspeth County in far west Texas (bordering New Mexico) observe Mountain Time (MT): MST (UTC-7) in winter and MDT (UTC-6) in summer. The Guadalupe Mountains National Park straddles the Texas-New Mexico border and is governed by Mountain Time. The vast majority of Texas including Dallas, Houston, San Antonio, Austin, Fort Worth, and Amarillo are on Central Time. When scheduling calls to Texas from the East Coast: the state is 1 hour behind ET. From Pacific Time: Texas is 2 hours ahead.

The core Mountain Time states are Colorado, Montana, New Mexico, Utah, and Wyoming (all entirely MT). Idaho is split: the southern two-thirds (including Boise and Twin Falls) are Mountain Time; the northern panhandle (Coeur d’Alene, Moscow) is Pacific Time. Nevada is mostly Pacific Time, but Elko and the northeast region are sometimes cited as MT influence areas. Kansas and Nebraska have western counties in Mountain Time. North Dakota and South Dakota have western portions in MT. Arizona is officially in the Mountain Time zone but does not observe DST, making it a unique case. New Mexico, Colorado, Utah, and Wyoming form the solid Mountain core, covering the Rocky Mountain region of the US.

No. Hawaii has not observed Daylight Saving Time since 1947 (it briefly followed war time in 1942-1945). The state operates permanently on Hawaii Standard Time (HST, UTC-10). The Hawaii-Aleutian Time Act of 1967 formally exempted Hawaii from DST under the Uniform Time Act. Because Hawaii is close to the tropics, the difference in sunset time between winter and summer is relatively small (around 90 minutes versus 4+ hours in northern states), making DST adjustments less meaningful than on the mainland. The practical result: each spring when the mainland springs forward, Hawaii effectively becomes 1 hour closer to the US mainland for the duration of summer, even though Hawaii itself makes no change.

Guam and the Northern Mariana Islands observe Chamorro Standard Time (ChST), UTC+10, year-round without DST. This places Guam 15 hours ahead of Eastern Standard Time (winter) and 14 hours ahead of Eastern Daylight Time (summer). When it is 9 AM Monday EST on the US East Coast, it is midnight (00:00) Tuesday in Guam. For Pacific Standard Time: Guam is 18 hours ahead in winter. The extreme time difference means Guam is effectively on a different calendar day from most of the US during business hours. US federal agencies, military commands, and contractors coordinating between Guam and the mainland typically schedule calls in the early morning US East Coast time (6-8 AM ET) which corresponds to 8-10 PM ChST in Guam the same evening.