Time Zone Converter

US Time Zones Explained

The time zone converter on this page converts any time between Eastern, Central, Mountain, Pacific, Alaska, and Hawaii time zones instantly. The contiguous United States spans four time zones — ET, CT, MT, and PT — from east to west. Alaska and Hawaii each have their own time zones, and Arizona uses Mountain Standard Time year-round without observing Daylight Saving Time.

All US time zones except Hawaii and Arizona shift one hour forward during Daylight Saving Time, which runs from the second Sunday in March through the first Sunday in November. This calculator automatically applies DST based on the date you enter, so the conversion is always accurate regardless of the time of year.

US Time Zone Quick Reference

Here are the standard UTC offsets for each US time zone, in both standard time (winter) and daylight time (summer):

• Eastern (ET): UTC-5 standard / UTC-4 daylight
• Central (CT): UTC-6 standard / UTC-5 daylight
• Mountain (MT): UTC-7 standard / UTC-6 daylight
• Pacific (PT): UTC-8 standard / UTC-7 daylight
• Alaska (AKT): UTC-9 standard / UTC-8 daylight
• Hawaii (HST): UTC-10, no DST
• Arizona (MST): UTC-7, no DST

Daylight Saving Time and Why It Matters

Daylight Saving Time (DST) shifts clocks forward by one hour in spring, which moves an hour of daylight from the morning to the evening. Most of the United States observes DST; the exceptions are Hawaii and most of Arizona. Because all other US zones shift simultaneously, the relative offsets between most US time zones remain constant year-round.

The practical impact: if you are scheduling a call between New York (ET) and Los Angeles (PT), the gap is always 3 hours, regardless of season. But if one party is in Arizona, the gap changes by one hour between summer and winter — Arizona does not shift while the rest of the country does.

When Scheduling Across Time Zones Goes Wrong

The most common time zone scheduling errors happen during the week when DST transitions occur (the second Sunday in March and the first Sunday in November). During those weeks, some people's devices may have updated while others have not, causing a 1-hour discrepancy. Always confirm meeting times with the date included when scheduling near transition dates.

Common Time Zone Conversions

These are the most frequently needed US time zone conversions. All values assume both zones are on the same DST schedule (i.e., not during Arizona edge cases):

• Eastern → Central: subtract 1 hour
• Eastern → Mountain: subtract 2 hours
• Eastern → Pacific: subtract 3 hours
• Central → Pacific: subtract 2 hours
• Pacific → Hawaii: subtract 2–3 hours (subtract 2 during DST, 3 during standard time)
• Eastern → Alaska: subtract 4–5 hours (subtract 4 during DST, 5 during standard time)

For military and 24-hour time conversions, use the military time calculator. For calculating how long a flight takes across time zones, see the flight time calculator.

Why the Date Matters for Time Zone Conversion

Most time zone converters let you enter just a time, but the correct UTC offset depends on the date because of Daylight Saving Time. A conversion from Eastern to Pacific at 2:00 AM on a DST transition date could produce different results depending on whether DST has taken effect. This calculator requires a date input to ensure accuracy — especially around the March and November transition weekends.

For most days of the year, a simple subtract-the-hours approach works fine. For precise scheduling, business communications, or any conversion on or near a DST transition date, use the date-aware conversion in this tool.