The USA has 6 time zones, or 9 if you count all US territories. Mainland USA spans 4 — Eastern (UTC-5), Central (UTC-6), Mountain (UTC-7), and Pacific (UTC-8). Alaska adds a 5th (UTC-9) and Hawaii a 6th (UTC-10). Daylight Saving Time shifts 5 of the 6 by +1 hour from mid-March through early November — Hawaii is the exception and stays flat year-round.
The Short Answer
Standard time zones west to east: Hawaii (UTC-10), Alaska (UTC-9), Pacific (UTC-8), Mountain (UTC-7), Central (UTC-6), Eastern (UTC-5). During Daylight Saving (mid-March to early November), all except Hawaii and most of Arizona shift one hour forward. That means from March to November, East and West coast are 3 hours apart; from November to March, still 3 hours apart (both shift together).
Full Explanation
The US time zones were standardized in 1883 by the railroads, long before the federal government made them official in 1918. Boundaries roughly follow state lines but with exceptions — Indiana, Kentucky, and Tennessee are split across two zones.
| Time zone | UTC offset (standard) | Major cities |
|---|
| Eastern (ET) | UTC-5 | New York, Washington DC, Miami, Atlanta, Boston |
| Central (CT) | UTC-6 | Chicago, Dallas, Houston, Nashville, New Orleans |
| Mountain (MT) | UTC-7 | Denver, Phoenix, Salt Lake City, Albuquerque |
| Pacific (PT) | UTC-8 | Los Angeles, San Francisco, Seattle, Las Vegas, Portland |
| Alaska (AKT) | UTC-9 | Anchorage, Juneau, Fairbanks |
| Hawaii (HST) | UTC-10 | Honolulu, Maui, all Hawaiian Islands |
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Common Exceptions
Not every state fits neatly into one zone.
- Arizona does NOT observe DST (except the Navajo Nation, which does)
- Hawaii does NOT observe DST
- Indiana is split — most of the state is Eastern, northwest and southwest corners are Central
- Kentucky is split — eastern half Eastern, western half Central
- Tennessee is split — eastern half Eastern, western half Central
- Florida Panhandle is Central; rest of Florida is Eastern
- Oregon and Idaho both have small slices in Pacific vs. Mountain
Flight schedules show local times. A 6pm flight from LA (Pacific) arriving NYC (Eastern) at 2am means you lose 3 hours on paper — clocks literally skip ahead. Account for this when planning overnight redeyes.
- Eastern Time serves the largest US population — about 47% of Americans
- The continental US is roughly 2,800 miles wide — a 3-hour time difference
- Alaska is 6 hours behind Eastern Time (during DST)
- Hawaii is 5-6 hours behind Eastern depending on DST
- Most US TV networks schedule in ET/PT — same show airs 3 hours apart
- US territories Puerto Rico, USVI, Guam and American Samoa have their own zones
Flying east is harder than flying west. Going LA to NYC, land early afternoon and force yourself to stay awake until 10pm local time. Your body adjusts in 2-3 days.
The USA has 6 time zones, or 9 if you count all US territories. Mainland USA spans 4 — Eastern (UTC-5), Central (UTC-6), Mountain (UTC-7), and Pacific (UTC-8). Alaska adds a 5th (UTC-9) and Hawaii a 6th (UTC-10). Daylight Saving Time shifts 5 of the 6 by +1 hour from mid-March through early November — Hawaii is the exception and stays flat year-round.
The Short Answer
Standard time zones west to east: Hawaii (UTC-10), Alaska (UTC-9), Pacific (UTC-8), Mountain (UTC-7), Central (UTC-6), Eastern (UTC-5). During Daylight Saving (mid-March to early November), all except Hawaii and most of Arizona shift one hour forward. That means from March to November, East and West coast are 3 hours apart; from November to March, still 3 hours apart (both shift together).
Full Explanation
The US time zones were standardized in 1883 by the railroads, long before the federal government made them official in 1918. Boundaries roughly follow state lines but with exceptions — Indiana, Kentucky, and Tennessee are split across two zones.
| Time zone | UTC offset (standard) | Major cities |
|---|
| Eastern (ET) | UTC-5 | New York, Washington DC, Miami, Atlanta, Boston |
| Central (CT) | UTC-6 | Chicago, Dallas, Houston, Nashville, New Orleans |
| Mountain (MT) | UTC-7 | Denver, Phoenix, Salt Lake City, Albuquerque |
| Pacific (PT) | UTC-8 | Los Angeles, San Francisco, Seattle, Las Vegas, Portland |
| Alaska (AKT) | UTC-9 | Anchorage, Juneau, Fairbanks |
| Hawaii (HST) | UTC-10 | Honolulu, Maui, all Hawaiian Islands |
🧮
USA Trip Cost Calculator
Plan your multi-city US trip and manage time zone changes
Common Exceptions
Not every state fits neatly into one zone.
- Arizona does NOT observe DST (except the Navajo Nation, which does)
- Hawaii does NOT observe DST
- Indiana is split — most of the state is Eastern, northwest and southwest corners are Central
- Kentucky is split — eastern half Eastern, western half Central
- Tennessee is split — eastern half Eastern, western half Central
- Florida Panhandle is Central; rest of Florida is Eastern
- Oregon and Idaho both have small slices in Pacific vs. Mountain
Flight schedules show local times. A 6pm flight from LA (Pacific) arriving NYC (Eastern) at 2am means you lose 3 hours on paper — clocks literally skip ahead. Account for this when planning overnight redeyes.
- Eastern Time serves the largest US population — about 47% of Americans
- The continental US is roughly 2,800 miles wide — a 3-hour time difference
- Alaska is 6 hours behind Eastern Time (during DST)
- Hawaii is 5-6 hours behind Eastern depending on DST
- Most US TV networks schedule in ET/PT — same show airs 3 hours apart
- US territories Puerto Rico, USVI, Guam and American Samoa have their own zones
Flying east is harder than flying west. Going LA to NYC, land early afternoon and force yourself to stay awake until 10pm local time. Your body adjusts in 2-3 days.