Timezone Converter

One input per line. Output is numbered to match the input order.
Pinned tools are listed in your favourites on the home page.Copies a link to this tool that carries your current input, so it opens ready to run.Gives you an iframe snippet for putting this tool on your own site.

Uses Intl.DateTimeFormat — no external library. Supports all IANA timezone names.

Ctrl+Enter Run  · Ctrl+Shift+C Copy  · Esc Clear

Understand Timezone Converter

Converts a date and time into any of 60+ IANA time zones, with daylight saving applied for the specific date you enter.

How it works

Conversion runs through the browser's Intl.DateTimeFormat API, which is backed by the IANA time zone database — the same dataset Linux, macOS, and most server runtimes use. That database stores the full history of each zone's rules, so America/New_York is resolved to UTC−5 for a January date and UTC−4 for a July one rather than to a single fixed offset. An input without a `Z` or a `±hh:mm` suffix is interpreted as UTC before conversion, so add the offset explicitly when your source time is local to somewhere else.

When to use it

  • Finding a meeting slot that is inside working hours in three countries at once
  • Translating a UTC server log timestamp into the local time a user reported a problem
  • Checking what a scheduled job configured in one region will actually run at in another
  • Confirming the offset for a specific historical date, where the answer differs from today's offset

Watch out for

  • Some local times do not exist and some happen twice. On a spring-forward day the clock jumps from 1:59 to 3:00, so 2:30 AM is not a real instant; on a fall-back day 1:30 AM occurs twice with two different offsets, and no conversion can tell you which one was meant.
  • Abbreviations are ambiguous and should not be trusted. CST is US Central, China Standard, and Cuba Standard; IST is India, Ireland, and Israel. Always identify a zone by its IANA name.
  • A fixed offset is not a time zone. Storing "UTC+2" instead of "Europe/Berlin" throws away the DST rules, so the value silently becomes wrong for half the year.
  • The zone rules come from the browser, so they are only as current as it is. Governments change DST rules with a few months' notice, and a stale device will convert a future date with the old rule.

Frequently Asked Questions

How to convert time zones?

Select a source timezone and a target timezone, then enter your date and time. The tool converts the moment to the target timezone accounting for UTC offset and daylight saving time. All 60+ IANA timezones are supported — search by city or zone name (America/New_York, Europe/London).

How to convert time zones in Excel?

In Excel, store datetimes in UTC in one column, then add the timezone offset in another: =A1 + (offset/24). For DST-aware conversion, use Power Query's DateTimeZone.ToLocal() or a helper column with VLOOKUP against a UTC offset table. This browser tool handles DST automatically.

How does this handle daylight saving time (DST)?

The converter uses the IANA timezone database via the browser's Intl.DateTimeFormat API. DST transitions are applied automatically — for example, America/New_York is UTC−5 in winter and UTC−4 in summer, and the tool uses the correct offset for the exact date you enter.

How to Use Timezone Converter

  1. Paste or type your input in the input area above.
  2. The tool processes your input automatically or click Run.
  3. Copy or download the result using the action buttons.
  4. Use Ctrl+Enter to run quickly from the keyboard.