The Complete Guide to USA Time Zones
Understanding the time zones of the United States can be complex. While many people are familiar with the four main time zones in the contiguous states, the full answer is more detailed. Officially, there are 9 standard time zones in the USA and its territories. This patchwork of time zones ensures that local times align reasonably well with the position of the sun across the vast expanse of the country.
This guide will break down all US time zones, from the East Coast to the remote Pacific islands. To see the current time in any of these locations live, we recommend using our World Clock dashboard, where you can add any American city for an at-a-glance view.
The Four Main Time Zones in America
These four zones cover the "lower 48" contiguous states and are the most referenced of all time zones in the US. If you're wondering "what are the time zones in USA for business and media?", these are the ones. From east to west, the US timing zones are:
- Eastern Time Zone (ET): This includes the Eastern Standard Time zone (EST; UTC-5) and Eastern Daylight Time (EDT; UTC-4). It covers major cities like New York, Miami, and Atlanta. As it includes the nation's capital and financial hub, it's often considered the de facto 'America time zone' for national announcements.
- Central Time Zone (CT): Includes Central Standard Time (CST; UTC-6) and Central Daylight Time (CDT; UTC-5). This zone covers a large portion of the central US, including cities like Chicago, Dallas, and New Orleans.
- Mountain Time Zone (MT): Includes Mountain Standard Time (MST; UTC-7) and Mountain Daylight Time (MDT; UTC-6). It's home to states like Colorado, Utah, and Arizona (which notably does not observe DST).
- Pacific Time Zone (PT): Includes Pacific Standard Time (PST; UTC-8) and Pacific Daylight Time (PDT; UTC-7). This is the time zone for West Coast states like California, Washington, and Oregon.
When scheduling a meeting across these zones, our Meeting Planner can instantly visualize the overlaps and find the best time for everyone.
Beyond the Mainland: All Time Zones in USA
To get the full list of United States time zones, we must include those used by states and territories outside the contiguous 48. These complete the list of 9 official time zones:
- Alaska Time Zone (AKST/AKDT): UTC-9 / UTC-8. Used by most of the vast state of Alaska.
- Hawaii-Aleutian Time Zone (HST): UTC-10. This zone covers Hawaii and the Aleutian Islands in Alaska. Hawaii is one of the few US states that does not observe Daylight Saving Time.
- Samoa Time Zone (SST): UTC-11. This zone is used in American Samoa.
- Chamorro Time Zone (ChST): UTC+10. Used in the US territories of Guam and the Northern Mariana Islands. Note that this zone is on the other side of the International Date Line.
- Atlantic Time Zone (AST): UTC-4. This zone is used by Puerto Rico and the U.S. Virgin Islands. They do not observe DST.
How to Easily Check Any US Time Zone
The easiest way to check the current time in any of the US states time zones is to use a reliable digital tool. Our Time Zone Converter allows you to instantly see the time difference between your local time and any American time zone. Simply type in a city, and the tool will handle all the complexities of DST and offsets for you, providing the precise, current local time.