United States time guide
US Time Zones
The United States spans several time zones, and the right answer depends on the location, date, and daylight-saving rules. For most business planning, start with Eastern, Central, Mountain, and Pacific Time, then add Alaska and Hawaii when those regions are part of the schedule.
EST or EDT, commonly used for New York, Washington, Atlanta, and many US market hours.
Central TimeCST or CDT, used by Chicago, Dallas, Houston, and many operations teams.
Mountain TimeMST or MDT, used by Denver, Salt Lake City, parts of Arizona, and Rocky Mountain schedules.
Pacific TimePST or PDT, used by Los Angeles, San Francisco, Seattle, and West Coast product launches.
Alaska TimeAKST or AKDT, important for Alaska operations, travel, logistics, and support coverage.
Hawaii TimeHST, generally stable against UTC because Hawaii does not observe daylight saving time.
US time zone quick table
Offsets below are typical standard and daylight offsets. Always check the calendar date for regions that change clocks.
| Zone | Common labels | Typical offset | IANA example |
|---|---|---|---|
| Eastern | EST / EDT | UTC-5 / UTC-4 | America/New_York |
| Central | CST / CDT | UTC-6 / UTC-5 | America/Chicago |
| Mountain | MST / MDT | UTC-7 / UTC-6 | America/Denver |
| Pacific | PST / PDT | UTC-8 / UTC-7 | America/Los_Angeles |
| Alaska | AKST / AKDT | UTC-9 / UTC-8 | America/Anchorage |
| Hawaii | HST | UTC-10 | Pacific/Honolulu |
Daylight saving exceptions matter
Most US scheduling shifts between standard time and daylight time, but not every location follows the same pattern. The US Department of Transportation notes that states may exempt themselves from daylight saving time, and NIST's local time FAQ lists Hawaii, several US territories, and most of Arizona as non-observing regions. Arizona also has a well-known Navajo Nation exception, so city-specific time zones are safer than broad labels.
For exact planning, avoid copying a fixed offset from a table into a future meeting. Use a city or IANA time zone, then choose the actual meeting date in a converter.
How to schedule across the US
A practical US meeting invite should include the date, the local time, and a recognizable zone label. For software and recurring meetings, use America/New_York, America/Chicago, America/Denver, America/Los_Angeles, America/Anchorage, or Pacific/Honolulu so the calendar can apply the right offset for the chosen date.
Common US time zone questions
Is Pacific always three hours behind Eastern?
Often, but exact comparisons should still use the date. Daylight-saving exceptions and local rules can make broad shortcuts risky.
What is the safest label for calendars?
Use a place-based IANA label such as America/New_York instead of only EST or EDT, especially for recurring meetings.
Where can I verify the data approach?
Read Time Zone Data And Accuracy for how this site handles IANA zones, browser time data, and correction reports.
For business meetings
If a meeting includes New York, Chicago, Denver, and Los Angeles, choose one reference city first and then convert the same moment for the other cities. Avoid writing only "9 AM US time" because that phrase is not precise. A clearer invite is "9:00 AM America/New_York" with the local equivalents listed for Central, Mountain, and Pacific participants.
For travel and events
Flights, hotel check-ins, conference agendas, and livestream announcements should be checked against the destination city. A trip from California to New York crosses from Pacific Time to Eastern Time, while a trip to Hawaii uses Hawaii Standard Time without the same daylight-saving pattern as most mainland destinations.
For support coverage
Customer support, sales coverage, and incident response schedules often need handoffs from Eastern morning through Pacific afternoon. Use the converter to find overlap hours, then document the final schedule with city names and IANA zones so teams in Arizona, Alaska, Hawaii, and remote locations are not forced to infer the intended offset.
Official references
For policy-level rules, check the US Department of Transportation daylight saving time page and the NIST Local Time FAQs. For live planning on this site, start with the time zone clocks hub or browse city time pages.
Data, review, and privacy
US time zone guidance combines official references with browser-supported IANA zones, but local rules and daylight-saving exceptions still need careful review. These links expose the site's data method, editorial review standards, correction channel, and advertising privacy information in the static page body.