Time Zone Converter
Converting Times Across World Time Zones
Scheduling across time zones is a daily challenge for remote teams, travelers, and anyone coordinating internationally. The complexity — daylight saving time that shifts twice a year, zones that don't align to whole hours, and the international date line — makes manual conversion error-prone. This converter handles all of it automatically using your browser's built-in time zone data.
How to Use This Calculator
Enter a date and time and select your source time zone. Hit Convert Time to see the equivalent time in all major world time zones simultaneously. Check "Use current time" to auto-fill the current local time in your source zone — useful for finding "what time is it now in Tokyo?" instantly.
How Time Zone Conversion Works
Every time zone is defined by its offset from UTC. New York is UTC−5 in winter (EST) and UTC−4 in summer (EDT). Tokyo is UTC+9 year-round. To convert New York (EST) 9:00 AM to Tokyo: 9 AM + 5 hours to UTC = 14:00 UTC → 14:00 + 9 = 23:00 Tokyo time.
Daylight Saving Time
DST shifts clocks forward by one hour in spring and back in fall — but not every country observes it:
- US and Canada: Second Sunday in March (spring forward) → first Sunday in November (fall back)
- Europe: Last Sunday in March → last Sunday in October
- Australia: Reversed seasons — first Sunday in October → first Sunday in April
- No DST: Japan, China, India, most of Africa, Iceland, most of Southeast Asia, Arizona (US)
This converter automatically applies the correct offset for any date you enter, including transitions.
Common Time Zone Quick Reference
- ET (EST/EDT): US East Coast — UTC−5/−4
- PT (PST/PDT): US Pacific — UTC−8/−7
- GMT/BST: UK — UTC+0 (winter) / UTC+1 (summer)
- CET/CEST: Central Europe — UTC+1 / UTC+2
- IST: India — UTC+5:30 (no DST, half-hour offset)
- JST: Japan — UTC+9 (no DST)
- AEDT/AEST: Sydney — UTC+11 / UTC+10
Frequently Asked Questions
How do I schedule a meeting across multiple time zones?
Find a time that falls within business hours (9 AM–5 PM) for as many participants as possible. US–Europe teams often use 9–11 AM ET (2–4 PM London). For US–Asia teams, there's usually no mutual business-hours overlap — someone will be meeting early morning or late evening. When overlap is impossible, rotate who takes the off-hours slot to share the burden fairly across the team.
Why does India have a half-hour offset (UTC+5:30)?
India chose a single national time zone as a compromise between the two zones that would otherwise bisect the country. The half-hour offset was needed to keep all regions in reasonable solar alignment. Nepal goes further — UTC+5:45. These fractional offsets exist because natural solar time (based on longitude) rarely aligns neatly with political boundaries.
What is UTC and how is it different from GMT?
For practical purposes, UTC and GMT are nearly identical — both represent time at the prime meridian (0° longitude). The technical distinction: GMT is a time zone, while UTC is the international time standard maintained by atomic clocks and doesn't observe daylight saving time. In software, aviation, finance, and science, UTC is always preferred for precision and unambiguity.
How does the international date line work?
The International Date Line (IDL) runs roughly along the 180° meridian through the Pacific Ocean. Cross it heading east (Asia to Americas) and you go back a day. Cross it heading west (Americas to Asia) and you gain a day. This is why a flight from Los Angeles to Tokyo can land "the next day" despite being only an 11-hour flight — the IDL is crossed during transit.
Can I use this to find the best time to call family abroad?
Yes — enter your local time and check when it falls within reasonable waking hours (8 AM–9 PM) for your destination. From the US East Coast to India: 8 PM ET = 5:30 AM IST (too early); 10 AM ET = 7:30 PM IST (perfect). For tracking when an international event begins in your local time, combine this with our Countdown Timer.