Free Time Zone Converter Online
Converting time zones by hand is error-prone — especially across the international date line or during daylight saving time changes. This free time zone converter lets you pick any source time and timezone, then shows the equivalent in 8 major cities simultaneously. Use this free online tool without any download or account.
Time Zone Converter
Times update automatically. DST is handled by your browser's Intl engine.
World Clock
UTC Offset Comparison
How This Free Time Zone Converter Works
This free time zone converter runs entirely in your browser — no server call, no external library. It uses the built-inIntl.DateTimeFormatAPI with IANA timezone identifiers to translate any source time into all 8 world clock cities at once. The calculation is instantaneous and works offline once the page has loaded.
IANA timezone strings are the international standard for naming timezones. Instead of abbreviations like "EST" — which is ambiguous — IANA uses location-based names such asAmerica/New_YorkorAsia/Kolkata. Every major operating system and browser ships with a complete IANA timezone database, so the converter always has access to the latest UTC offset rules without needing an update.
Daylight saving time is handled automatically. When you enter a date in summer for a US city, the browser engine applies EDT (UTC-4) rather than EST (UTC-5) without any input from you. The same time zone converter correctly switches to winter time on the relevant transition Sunday. This means you can trust the output even when scheduling across seasons or planning months ahead. No manual DST adjustment is ever needed.
Daylight Saving Time: What to Watch For
Who Observes DST
The US, Canada, and most of Europe observe daylight saving time. Russia, China, Japan, India, and most of Africa do not — their UTC offset stays constant year-round.
When It Changes
In the US, clocks spring forward on the second Sunday in March and fall back on the first Sunday in November. The EU transitions on the last Sunday in March and the last Sunday in October — sometimes a week or two apart from the US switch.
The Hidden Trap
A recurring meeting at "9 AM New York" can silently shift by an hour for European participants during the gap between the US and EU transitions. A reliable time zone converter surfaces this by showing the exact date alongside the time.
Why This Converter Handles It
The browser's Intl API always knows the correct UTC offset for any IANA timezone at any point in time — past, present, or future. You never need to remember which cities are currently on standard vs. daylight time.
Common Time Zone Abbreviations
Abbreviations are a quick shorthand, but they can be ambiguous — "CST" means Central Standard Time in North America and China Standard Time in Asia. When using a time zone converter for international scheduling, always confirm the IANA identifier or city name rather than relying solely on abbreviations.
When You Need a Time Zone Converter
Remote Teams
Scheduling a standup across New York, London, and Singapore means juggling three different offsets — and potentially two DST transitions mid-year. A time zone converter removes the guesswork and prevents early-morning or late-night surprises for any participant.
International Flights
Flight departure and arrival times are shown in local time at each airport. A time zone converter lets you calculate your actual travel duration and figure out what time your body will think it is when you land — useful for managing jet lag.
Global Broadcasts
Live events — sports finals, product launches, streaming premieres — are announced in a single timezone. Convert once with this free online tool and share the local time with your audience in every region without recalculating manually each time.
Trading Hours
Stock exchanges, forex markets, and crypto sessions each open and close on a fixed local schedule. Knowing when the New York Stock Exchange opens in Tokyo time — or when the London forex session overlaps with New York — is essential for traders operating across continents.
Did You Know?
38
Distinct UTC offsets in use worldwide — some at 30- or 45-minute increments. India is UTC+5:30; Nepal goes further at UTC+5:45.
1884
Year the International Meridian Conference standardized Greenwich as the prime meridian and established the world's time zone system, creating the need for the modern time zone converter.
1 day
Crossing the International Date Line westward adds a full calendar day — why you can "arrive before you leave" on a flight to New Zealand.
Frequently Asked Questions
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