Time Zone Converter

What Is a Time Zone Converter?

A time zone converter is a tool that translates a specific date and time from one time zone to another. Time zones exist because Earth is a sphere — as it rotates, different locations experience solar noon at different times. Without time zones, a single global clock would show different solar times simultaneously, making scheduling between cities impossible. The world is divided into roughly 40 official time zones, each typically one hour apart, though some countries offset by 30 or even 45 minutes. A time zone converter takes the guesswork out of these offsets, giving you the exact equivalent time across any two zones in the world.

Our free online time zone converter goes beyond basic UTC arithmetic. It uses the browser's built-in Intl.DateTimeFormat API, which taps into your device's system time zone database — the same data your computer relies on for accurate clock display. That means you get accurate, locale-aware conversions for hundreds of regions, including daylight saving time adjustments that manual offset calculations often miss.

1. Select your source zone — Choose the time zone where your input time originates from the first dropdown menu. The list includes major world cities across all inhabited continents (e.g., New York, London, Tokyo, Sydney, Dubai).
2. Select your target zone — Choose the destination time zone from the second dropdown. The tool supports hundreds of IANA timezone identifiers (e.g., America/Los_Angeles, Europe/Paris, Asia/Shanghai), ensuring broad global coverage.
3. Enter date and time — Type the date and time you want to convert into the input field. You can use a 12-hour or 24-hour format; the converter handles both.
4. Click "Convert Time" — Press the button to trigger the conversion. JavaScript's native Intl.DateTimeFormat API performs the calculation, automatically accounting for Daylight Saving Time rules for both zones.
5. Read the result — The converted time appears immediately, showing the equivalent date and time in the target zone, including the day of the week. If the target date differs from the source (crossing midnight or the International Date Line), that is reflected in the output.
6. Check live city times — Below the result, a live clock section updates every second, showing the current time in several major cities so you can quickly verify against real-world reference times.

These are the most frequently searched time zone conversions for international business, travel, and remote collaboration:

• New York → London: 5 hours ahead (UTC-5 to UTC+0, or UTC-4 to UTC+1 during DST)
• London → Tokyo: 9 hours ahead (UTC+0 to UTC+9, or UTC+1 to UTC+9 during DST)
• Beijing → New York: 12-13 hours behind (UTC+8 to UTC-5/UTC-4)
• Sydney → London: 10-11 hours behind (UTC+10/UTC+11 to UTC+0/UTC+1)
• Dubai → London: 3-4 hours ahead (UTC+4 to UTC+0/UTC+1)
• Los Angeles → Tokyo: 16-17 hours ahead (UTC-8/UTC-7 to UTC+9)
• Singapore → London: 7-8 hours ahead (UTC+8 to UTC+0/UTC+1)
• Shanghai → San Francisco: 15-16 hours behind (UTC+8 to UTC-8/UTC-7)

These offsets shift during Daylight Saving Time transitions. Always use a real-time converter (like the one above) for critical scheduling — especially during the weeks when zones "spring forward" or "fall back" at different dates.