How does the timezone converter work?

The tool uses Intl.DateTimeFormat with the IANA timezone database that ships in every modern browser. The date and time you enter are treated as wall-clock time in the source zone, then the same absolute moment is formatted in the target zone.

Is the IANA database kept up to date?

The database ships with your browser and is updated whenever the browser updates. That means current daylight saving rules and recent zone changes are reflected automatically.

How many time zones can I convert between?

Every IANA zone exposed by Intl.supportedValuesOf('timeZone') is available, currently over 400 zones covering every region of the world.

Is my data sent to a server?

All processing runs in your browser. The dates and zones you enter are never sent anywhere.

Does the tool handle daylight saving transitions?

Yes. Conversions for any specific date use the daylight saving rules in effect on that date, including offsets that are not whole hours.

Timezone converter

Timezone converter is a time tool that translates any moment between time zones using the IANA timezone database. It auto-detects your local zone, supports 400+ IANA zones, and honours daylight saving rules for any date. The tool runs in your browser.

From timezoneTo timezone

Date and time (wall clock in source zone)

In America/New_York (UTC-04:00)

Monday, May 25, 2026 at 6:46:00 PM EDT

Source: UTC (UTC+00:00)

Monday, May 25, 2026 at 10:46:00 PM UTC

Quick target zones

Dedicated pages

Direct links for common timezone use cases.

Timezone Converter

Convert any time between time zones using the IANA database. Instant in-browser results with shortcuts for major cities and UTC.

Time Difference Calculator

Calculate the time difference between two cities or time zones. Pick a moment and see the equivalent local time in both zones instantly.

Meeting Planner Across Timezones

Plan meetings across time zones. Pick your local time and see the matching time in another zone instantly, with shortcuts for major cities.

How to convert a time between timezones

Pick the source timezone using the dropdown. Your local zone is detected automatically on first load.
Pick the target timezone, or use one of the quick-city shortcuts on the side panel.
Enter the date and time, or click Now to fill it with the current moment.
Read the converted local time in the target zone. The source time is shown below for context.

Common uses

Scheduling a meeting across two or more cities
Working out when a webinar, livestream, or product launch happens in your local time
Coordinating release deadlines with distributed teams, often alongside the Unix timestamp converter for log analysis
Planning travel arrivals and departures across multiple time zones, with the date calculator for trip durations

Technical specification

Algorithm or formula: The wall-clock time entered in the source zone is converted to a UTC instant, then re-formatted in the target zone using Intl.DateTimeFormat with the appropriate timeZone option.
Browser API or library: Native Intl.DateTimeFormat and Intl.supportedValuesOf("timeZone"), both backed by the IANA timezone database bundled with the browser's ICU library.
Input limits: 400+ IANA zones depending on the browser. Date range follows ECMAScript Date limits (±100,000,000 days from 1970-01-01).
Output: Converted local time in the target zone, with offset, day-of-week, and a confirmation of the source time for context.
Known limitations: Historical DST rules depend on the browser's ICU data version. Some recently changed zones may lag a release behind the upstream tz database.

Frequently asked questions

How does the timezone converter work?: The tool uses Intl.DateTimeFormat with the IANA timezone database that ships in every modern browser. The date and time you enter are treated as wall-clock time in the source zone, then the same absolute moment is formatted in the target zone.
Is the IANA database kept up to date?: The database ships with your browser and is updated whenever the browser updates. That means current daylight saving rules and recent zone changes are reflected automatically.
How many time zones can I convert between?: Every IANA zone exposed by Intl.supportedValuesOf('timeZone') is available, currently over 400 zones covering every region of the world.
Is my data sent to a server?: All processing runs in your browser. The dates and zones you enter are never sent anywhere.
Does the tool handle daylight saving transitions?: Yes. Conversions for any specific date use the daylight saving rules in effect on that date, including offsets that are not whole hours.

Reviewed and tested May 25, 2026.