🌍 Time zone conversion • Supports DST (Daylight Saving Time) • US time zones included

📅 Date & Time

🌎 From Time Zone

🌍 To Time Zone

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Converted time

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From zone UTC offset

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To zone UTC offset

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Hour difference

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Daylight Saving

Time zone calculator - convert time between US and international zones

Convert time zones instantly — fast, free, no signup

US Time Zones Reference

Understanding Time Zone Conversion

A time zone is a region where the same standard time is used. The world is divided into 24 time zones, each approximately 15 degrees of longitude apart. UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks and time.

Time Conversion Formula: Target Time = Source Time + (Target Offset - Source Offset)

Where offsets are measured in hours from UTC

US Time Zones Overview

Eastern Time (ET): UTC-5 (EST) / UTC-4 (EDT) — New York, Washington DC, Atlanta
Central Time (CT): UTC-6 (CST) / UTC-5 (CDT) — Chicago, Dallas, Mexico City
Mountain Time (MT): UTC-7 (MST) / UTC-6 (MDT) — Denver, Phoenix (no DST), Salt Lake City
Pacific Time (PT): UTC-8 (PST) / UTC-7 (PDT) — Los Angeles, San Francisco, Seattle
Alaska Time (AKT): UTC-9 (AKST) / UTC-8 (AKDT) — Anchorage, Juneau
Hawaii Time (HT): UTC-10 (HST) — Honolulu (no DST)

How to Use This Time Zone Calculator

Select your desired date and time using the datetime picker
Choose the source time zone (where you're converting from)
Choose the target time zone (where you're converting to)
Click "Convert Time" to see the converted time and time difference
View the US time grid to see current times across all US zones

Daylight Saving Time (DST)

Daylight Saving Time is observed in most of the United States from the second Sunday in March to the first Sunday in November. During DST, clocks are set forward by one hour. Arizona (except Navajo Nation) and Hawaii do not observe DST. This calculator automatically accounts for DST based on the selected date.

International Time Zones

UTC/GMT: Coordinated Universal Time — the global time standard
UK (GMT/BST): UTC+0 (GMT) / UTC+1 (BST) — London, Manchester, Edinburgh
CET (Central European): UTC+1 (CET) / UTC+2 (CEST) — Paris, Berlin, Rome
GST (Gulf Standard): UTC+4 — Dubai, Abu Dhabi (no DST)
IST (India Standard): UTC+5:30 — Mumbai, Delhi (no DST)
JST (Japan Standard): UTC+9 — Tokyo, Osaka (no DST)
AET (Australian Eastern): UTC+10 (AEST) / UTC+11 (AEDT) — Sydney, Melbourne

Common Time Zone Conversions

EST to PST: Subtract 3 hours (Eastern is 3 hours ahead of Pacific)
EST to UTC: Add 5 hours during standard time, 4 hours during DST
PST to UK: Add 8 hours (Pacific is 8 hours behind UK)
CST to EST: Add 1 hour (Central is 1 hour behind Eastern)
MST to CST: Add 1 hour (Mountain is 1 hour behind Central)

Frequently Asked Questions

What is UTC? — Coordinated Universal Time is the primary time standard used worldwide for time zone offsets.
How many time zones are in the US? — The US has 9 time zones including territories: Eastern, Central, Mountain, Pacific, Alaska, Hawaii, Atlantic, Samoa, and Chamorro.
Does Arizona observe Daylight Saving Time? — Most of Arizona does not observe DST, except the Navajo Nation.
What's the best time for a US-UK meeting? — 3pm UK time is 10am Eastern, 9am Central, 8am Mountain, 7am Pacific.
How do I calculate time zone differences? — Subtract the source UTC offset from the target UTC offset. Positive means ahead, negative means behind.

Time Zone Calculator