Time Zone Converter

The Timezone Converter translates a specific time between any two (or many) timezones around the world. Remote teams, international clients, news events, and travel itineraries all hit this problem: a meeting scheduled at 3 PM London time — what time is that in New York, Tokyo, Sydney, Los Angeles, and Berlin? A stock market opens at 9:30 EST — what time is that in Bangalore? A flight lands at 14:45 local destination time — what time is that where I am now?

This tool handles timezone math correctly, including the many edge cases that trip up casual converters. Daylight saving transitions are handled based on the IANA timezone database (which tracks every timezone rule change globally). Cities that do not observe DST (Arizona, Hawaii, most of Asia) get the right offset year-round. Historical DST changes are supported (some countries have changed rules recently). The converter shows multiple timezones simultaneously — up to ten on screen — so you can see at a glance when a meeting works for everyone or when there is no overlap. Paste a source time and timezone, watch every target city update instantly.

Timezone math is deceptively complex because the rules change. The IANA timezone database (tzdata) maintains authoritative timezone definitions including historical rule changes, DST transitions, and offsets. This tool uses modern browser timezone APIs (the Intl object) which internally use the same IANA rules, so results match server-side libraries (moment-timezone, Luxon, date-fns-tz) and OS clocks.

A timezone is more than just a UTC offset. America/New_York is not always UTC-5; during DST it is UTC-4. The tool uses full timezone identifiers (like America/New_York, Europe/Berlin, Asia/Tokyo) rather than offset strings, which is the correct approach for accurate conversion across arbitrary dates.

DST transitions create two-hour ambiguous periods twice a year. In spring, clocks skip an hour — a local time like 2:30 AM does not exist on the transition day. In fall, clocks fall back and a local time like 1:30 AM happens twice. The converter handles these correctly using standard date parsing (which picks the first occurrence for ambiguous times and moves forward past skipped times).

Offsets are not always on the hour. India Standard Time is UTC+5:30. Nepal is UTC+5:45. Newfoundland is UTC-3:30. The converter displays offsets accurately to the minute and handles the math correctly.

Historical timezone changes happen regularly. Russia abolished DST in 2011, restored it, changed zones. Egypt reintroduced DST in 2023. Many tools cached older rules and give wrong answers for recent dates. IANA tzdata updates reflect these changes promptly; this tool uses current tzdata via browser APIs, so conversions for any date from 1900 to the distant future should be accurate.

The tool also supports arbitrary UTC offset input for scenarios where only the offset is known (say from a GPS coordinate without a full timezone identifier). This is less precise — without knowing DST rules, future conversions may be wrong — but useful for one-off calculations.

Compared to Google (\"3 PM London in NYC\"), this tool shows multi-city comparison, meeting-window overlap, and DST-aware conversion in one interface. For single quick lookups search is fine; for scheduling across many cities this tool wins.

Compared to WorldClock apps that show only the current time in various cities, this converter lets you pick any date and time (past, future, or specific upcoming meeting) and see how it maps everywhere. WorldClocks are great for knowing what time it is somewhere now; this tool is for planning.

Compared to calendar apps with timezone support (Google Calendar, Outlook, Fantastical), this tool is faster for ad-hoc what-time-is-this-there queries without creating a calendar event. For scheduled meetings with invitees, still use a calendar — the converter\u2019s role is exploratory.