Time Zone Converter
The US time zone converter lets you instantly translate any time from one American time zone to another. The United States spans six standard time zones: Eastern (ET), Central (CT), Mountain (MT), Pacific (PT), Alaska (AK), and Hawaii (HI). Scheduling across these zones is a daily challenge for remote teams, business calls, webinars, travel, and broadcast media. Getting it wrong by even one hour can mean a missed meeting or a misread deadline.
This tool uses the Intl.DateTimeFormat API with IANA time zone identifiers, which means Daylight Saving Time transitions are handled automatically based on the selected date. Hawaii and most of Arizona do not observe DST, so their offsets stay fixed year-round. Simply enter a time and date, choose a source time zone, and select the target zone. The converter displays the equivalent local time and date in the target zone, together with the UTC offset for both zones on the selected date.
How the conversion works
1. Combine input date and time into an ISO string
2. Parse as a Date in the source time zone using Intl.DateTimeFormat
3. Re-format the same instant in the target time zone
4. Read the UTC offset for each zone on the selected date
US time zone reference
Eastern Time (ET) covers the northeastern and southeastern states including New York, Florida, Georgia, and Ohio. Central Time (CT) covers states including Texas, Illinois, and Minnesota. Mountain Time (MT) covers states including Colorado, Arizona (partial), and Utah. Pacific Time (PT) covers California, Washington, Oregon, and Nevada. Alaska Time (AK) covers most of Alaska. Hawaii Time (HI) covers Hawaii and does not observe Daylight Saving Time.
Daylight Saving Time in the US
Most of the US advances clocks by one hour on the second Sunday in March and falls back on the first Sunday in November. Hawaii and most of Arizona do not participate. During DST, Eastern is UTC-4, Central is UTC-5, Mountain is UTC-6, Pacific is UTC-7, and Alaska is UTC-8. During standard time, each zone is one hour further behind UTC.
Time zone converter: frequently asked questions
How many time zones does the US have?
The contiguous United States spans four main time zones: Eastern (ET), Central (CT), Mountain (MT), and Pacific (PT). Including non-contiguous states, there are six standard zones: Alaska (AK) and Hawaii (HI) add two more. Some territories such as Puerto Rico and Guam use additional zones not covered here.
Does the US observe Daylight Saving Time everywhere?
No. Hawaii does not observe Daylight Saving Time and stays on Hawaii Standard Time (HST, UTC-10) year-round. Most of Arizona also does not observe DST and stays on Mountain Standard Time (MST, UTC-7) year-round, though the Navajo Nation within Arizona does observe DST. All other US states observe the spring-forward, fall-back change.
What is the difference between ET and EDT?
ET refers to the Eastern Time zone in general. During Daylight Saving Time (roughly March to November), the zone uses Eastern Daylight Time (EDT), which is UTC-4. During standard time (roughly November to March), it uses Eastern Standard Time (EST), which is UTC-5. This calculator uses your device's clock, so DST is handled automatically.
How do I convert Eastern Time to Pacific Time?
Pacific Time is 3 hours behind Eastern Time. So if it is 12:00 PM ET, it is 9:00 AM PT. During the brief periods each year when one zone has switched to DST and the other has not yet, the difference may be 2 hours. This calculator accounts for DST automatically.
What is UTC?
UTC stands for Coordinated Universal Time. It is the global time standard used as a reference point for all other time zones. UTC does not observe Daylight Saving Time. Eastern Standard Time is UTC-5, Central Standard Time is UTC-6, Mountain Standard Time is UTC-7, Pacific Standard Time is UTC-8, Alaska Standard Time is UTC-9, and Hawaii Standard Time is UTC-10.
Official sources
- NIST Time and Frequency Division: US Time Zones.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.