Timezone Converter

Easily convert time between different timezones. Schedule international meetings and plan events with our free, accurate, and user-friendly world clock converter.

A timezone converter translates a date and time from one timezone to another, accounting for differences in UTC offset, daylight saving time (DST) rules, and historical timezone changes. It eliminates the mental arithmetic and error-prone manual calculations required when scheduling across timezones. This tool uses your browser's built-in Intl.DateTimeFormat API for accuracy and runs entirely client-side.

Convert time across timezones without sharing your data

Accurate DST-aware conversions using your browser's native Internationalization API. Add unlimited target timezones, compare side-by-side, and plan with confidence.

All timezones

Instant results

Free unlimited

How to use

1
Set a Date and Time
Select the 'source' time you want to convert.
2
Select Your Timezone
Choose the timezone for the source time (defaults to your local).
3
Add Target Timezones
Add locations you want to compare.
4
Compare
Review the converted times, which account for DST automatically.

Never Miss an International Call Again

For Global Teams

Find the perfect time for meetings. See everyone's local time at a glance.

For Travelers

Plan trips and calls back home. Know the exact time difference.

For Events

Schedule webinars and announce the correct time for your global audience.

DST-Aware

Automatically handles Daylight Saving Time transitions for all 400+ IANA timezones.

Understanding Timezones and Time Conversion

Why timezone conversion is harder than it seems

Timezones are not simply offsets from UTC -- they are complex political and geographical regions with their own rules. There are 38 local times in use worldwide, with offsets ranging from UTC-12:00 to UTC+14:00. Some timezones use 30-minute or 45-minute offsets (India is UTC+5:30, Nepal is UTC+5:45). Daylight Saving Time (DST) adds another layer of complexity: not all countries observe DST, those that do start and end on different dates, and the dates change year to year. The United States, EU, and Australia all have different DST schedules.

Historical timezone changes make things even harder. Countries frequently change their timezone rules -- Russia abolished DST in 2014, North Korea created its own timezone (UTC+8:30, later reverted to UTC+9) in 2015, and Chile has changed its DST rules multiple times. The IANA Time Zone Database (tzdata) tracks all these changes and is updated several times per year. Your browser uses this database via the Intl API, ensuring that historical timezone conversions are accurate. This is why you should never hard-code timezone offsets -- always use the IANA timezone name (e.g., 'America/New_York', not 'UTC-5').

A common mistake is confusing timezone offset with timezone. 'UTC-5' is an offset that changes twice a year for New York (UTC-5 during EST, UTC-4 during EDT). 'America/New_York' is a timezone that encapsulates the rules for when to switch. The Intl.DateTimeFormat API in modern browsers handles this correctly -- you specify the IANA timezone name and the API applies the correct offset for any given date and time.

Best practices for scheduling across timezones

Always store and transmit times in UTC. Convert to local time only for display. This eliminates ambiguity -- a UTC timestamp means the same thing everywhere in the world. When displaying times to users, use the Intl.DateTimeFormat API with the user's timezone (obtained from Intl.DateTimeFormat().resolvedOptions().timeZone) to show times in their local timezone automatically. For event scheduling, always include the timezone in the display (e.g., '3:00 PM EST' or '3:00 PM UTC-5') and consider using ISO 8601 format with timezone offset (e.g., 2024-01-15T15:00:00-05:00) for machine-readable data.

When scheduling meetings across timezones, use a tool that shows all participants' local times side by side. Be mindful of DST transitions -- a recurring meeting at '9 AM EST' doesn't exist during the DST gap in March. Also, some dates don't exist in all timezones: when the US springs forward, 2:00 AM to 3:00 AM doesn't exist, and when it falls back, 1:00 AM to 2:00 AM happens twice. These edge cases are handled automatically by the Intl API but can cause bugs if you're doing manual offset arithmetic.

Understanding Timezones

The Basics

Timezones are offsets from UTC (Coordinated Universal Time).

Daylight Saving

Many regions shift clocks in summer. Our tool handles these complex rules automatically.

IANA Standard

Uses the IANA timezone database — the same standard used by operating systems and programming languages worldwide.

Recurring Meetings

Plan meetings that account for upcoming DST transitions in March and November.

How does this compare to other timezone converters?

A side-by-side comparison of popular timezone conversion tools.

Feature	NovaTools	TimeAndDate.com	WorldTimeBuddy
Privacy (no server)	100% local	Server-side	Server-side
IANA timezone database	Browser Intl API
DST-aware
No registration			(for saving)
Mobile friendly		Limited
Works offline

Our converter uses your browser's built-in Intl.DateTimeFormat API, which is maintained by browser vendors and updated with the latest IANA timezone data. All conversions happen locally -- no data leaves your device.

FAQ

What are IANA timezones?

IANA timezones (e.g., 'America/New_York', 'Europe/London', 'Asia/Tokyo') are a standard format maintained by the Internet Assigned Numbers Authority. They are preferred by programmers because they handle historical changes and Daylight Saving Time rules automatically. Unlike fixed UTC offsets (e.g., UTC-5), IANA timezones encode the complete rules for when DST starts and ends, historical timezone changes, and exceptions specific to each region. For example, 'America/Indianapolis' uses Eastern Time but did not observe DST before 2006 — only the IANA name captures this correctly. Most programming languages, databases, and operating systems support IANA timezone names natively.

Does this tool handle Daylight Saving Time (DST)?

Yes. Our tool uses your browser's built-in Internationalization API (`Intl.DateTimeFormat`) to accurately handle DST adjustments for any given date. This means if you convert a time from New York to London in January, the tool correctly applies a 5-hour difference (EST → GMT). But if you convert the same time in July, it applies a 4-hour difference (EDT → BST) because both cities observe DST — though on different dates. The tool automatically accounts for the complex and sometimes changing DST rules of over 400 timezone regions worldwide, including regions that have recently abolished DST (like the EU's proposed changes) or never observed it (like Arizona and Hawaii).

What is the difference between UTC and GMT?

Practically, they are the same for most everyday purposes. UTC (Coordinated Universal Time) is the modern scientific standard defined by atomic clocks, while GMT (Greenwich Mean Time) is a historical timezone based on the mean solar time at the Royal Observatory in Greenwich, London. UTC is the basis for all modern timezone calculations — every IANA timezone is defined as an offset from UTC. GMT is still used colloquially (especially in the UK) and is often used interchangeably with UTC+0. This tool uses UTC as the reference for all conversions, as it is the standard used by browsers, servers, and APIs worldwide.

How accurate are the timezone conversions?

The conversions use your browser's built-in timezone database, which is maintained by the IANA and updated regularly by browser vendors (Chrome, Firefox, Safari, Edge). The database includes historical timezone changes going back decades, current DST rules, and planned future changes. However, if a government announces a last-minute timezone or DST change (which happens occasionally), your browser's database may not reflect it until the next browser update. For mission-critical scheduling (e.g., financial trading, aviation), always verify with an authoritative source. For everyday meeting scheduling and event planning, the tool's accuracy is more than sufficient.

Can I compare multiple timezones at once?

Yes. The tool lets you add an unlimited number of target timezones. Each timezone shows the converted time side-by-side, making it easy to find a meeting time that works for everyone. You can add timezones by searching for city names (e.g., 'Tokyo', 'New York', 'Berlin') or by selecting from the IANA timezone list. The tool also highlights business hours (9 AM to 6 PM) in each timezone, so you can quickly identify overlap windows that work for all participants. Remove timezones you no longer need with a single click.

How do I schedule a recurring meeting across timezones?

Set the source time to your preferred meeting time, add all participants' timezones, and check that the converted times fall within reasonable working hours for everyone. Be aware of DST transitions: a meeting at 9 AM New York time may shift by one hour in London and Tokyo when DST starts or ends, because different regions change clocks on different dates. For recurring meetings, we recommend reviewing the converted times every March and November (when most DST transitions occur) to ensure the meeting time still works for all participants.

Why does the tool show my local time?

The tool defaults to your browser's local timezone as the source timezone, which is determined by your operating system's timezone setting. This is convenient because most users want to convert from their own local time to other timezones. You can change the source timezone to any IANA timezone if you need to convert between two timezones that are not your own — for example, converting from Tokyo time to London time when you are in New York. The tool also displays the UTC offset next to each timezone for quick reference.

Is my scheduling data private?

Yes. All timezone conversions happen locally in your browser using the `Intl.DateTimeFormat` API. No meeting times, timezone selections, or usage patterns are transmitted to our servers. The tool does not require an account, does not use cookies to track your activity, and does not store your data in local storage. When you close the browser tab, all timezone selections and converted times are cleared from memory. This makes the tool safe to use for confidential meetings, executive scheduling, or any scenario where meeting times should not be exposed to third parties.

Accurate and Private

This tool uses your browser's local time engine and the built-in Internationalization API (`Intl.

DateTimeFormat`) for all timezone conversions.
No meeting times, timezone selections, participant locations, or usage patterns are ever transmitted to our servers, stored in a database, or shared with third parties.
The tool does not require an account, does not use cookies to persist your settings, and does not employ analytics scripts to track your scheduling activity.
All timezone data — including the IANA timezone database and DST rules — is bundled with your browser and processed locally on your device.
When you close the browser tab, all converted times and timezone selections are cleared from memory immediately.

This makes the tool safe to use for confidential meetings, executive scheduling, client calls, and any scenario where meeting times should not be exposed to third-party servers.

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