Time Zone Converter
Convert time between any two cities or time zones. Handles daylight saving time automatically. Free, instant, and accurate.
About This Tool
Coordinating across time zones is a daily challenge for remote teams, international travelers, and anyone scheduling calls with people in other parts of the world. This converter eliminates the mental math by using JavaScript native Intl.DateTimeFormat API, which handles daylight saving time transitions automatically and accurately.
Unlike converters that use hardcoded UTC offsets, this tool dynamically calculates time differences based on the IANA time zone database. This means it correctly handles edge cases like countries that observe DST on different dates (the US and Europe switch on different weekends), regions that have changed their UTC offset in recent years, and the handful of time zones that operate on half-hour or 45-minute offsets (India at UTC+5:30, Nepal at UTC+5:45, Chatham Islands at UTC+12:45).
The converter includes presets for the 20 most-searched cities: New York, London, Tokyo, Paris, Sydney, Dubai, Singapore, Hong Kong, Berlin, Mumbai, Shanghai, Los Angeles, Chicago, Toronto, Seoul, Bangkok, Istanbul, Moscow, Sao Paulo, and Lagos. These cover every major financial market, tech hub, and business center. You can also select from the full list of IANA time zones for locations not in the presets.
The tool shows both the converted time and contextual information: the current time in both zones (updating live), whether the date changes in the destination (the "next day" indicator), and the DST status for both locations. The time difference is displayed as a positive or negative hour offset, making it easy to understand the relationship between the two zones.
All processing happens in your browser. No time data is sent to any server. The tool uses the system clock of your device for "current time" calculations, so make sure your device clock is accurate for the live features.
How to Use
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1
Select source and destination
Choose your source city or time zone from the dropdown, then select the destination. Use the preset buttons for quick selection.
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2
Set the date and time
Pick the date and enter the time using the hour, minute, and AM/PM selectors. Today date and current time are set by default.
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3
Read the converted time
The destination time appears instantly. Check for the "next day" indicator if the date changes, and note the DST status for both zones.
Where Does This Data Come From?
Time zone conversions use the JavaScript Intl.DateTimeFormat API backed by the IANA Time Zone Database (also known as the Olson database). This is the same database used by operating systems, programming languages, and internet standards worldwide. The tool uses Intl.supportedValuesOf("timeZone") to enumerate available zones, ensuring compatibility with the browser native implementation. DST detection works by comparing the UTC offset at the selected date with the UTC offset at the opposite solstice -- if they differ, DST is in effect for the current date. All calculations are performed client-side with no external API calls.
