World Clock
Display current time in all time zones around the world
World Clock
Current time in all timezones around the world
How it works
This tool uses the native JavaScript Intl API to get all supported timezones and display their current local time.
// Get all supported timezones
const timeZones = Intl.supportedValuesOf('timeZone');
// Get time for a specific timezone
const timeString = new Date().toLocaleTimeString('en-US', {
timeZone: 'America/New_York',
hour: '2-digit',
minute: '2-digit',
second: '2-digit',
hour12: false,
});
Intl.supportedValuesOf() Explained
Intl.supportedValuesOf() is a JavaScript method that returns an array of all supported values for a given locale option.
// Available options:
Intl.supportedValuesOf('timeZone'); // Returns all timezone names
Intl.supportedValuesOf('locale'); // Returns all locale tags
Intl.supportedValuesOf('calendar'); // Returns all calendars (gregory, chinese, etc.)
Intl.supportedValuesOf('numberingSystem'); // Returns all number systems (arab, latn, etc.)
Example output:
Intl.supportedValuesOf('timeZone');
// ['Africa/Abidjan', 'Africa/Cairo', 'America/New_York', 'Asia/Shanghai', 'Europe/London', ...]
Why use IANA Timezone Names?
IANA timezone names (e.g., Asia/Shanghai, America/New_York) are standardized identifiers that:
- Uniquely identify a timezone's rules
- Include historical timezone changes (DST, etc.)
- Are supported by all modern browsers and Node.js
Common timezone prefixes:
Africa/- African citiesAmerica/- North & South American citiesAsia/- Asian citiesEurope/- European citiesPacific/- Pacific Ocean citiesAustralia/- Australian cities
Browser Compatibility
The Intl.supportedValuesOf() method is supported in:
- Chrome 99+
- Edge 99+
- Safari 15.4+
- Firefox 101+
Date Object Explained
The Date object represents a single moment in time.
// Create current time
const now = new Date();
// Get time in specific timezone
now.toLocaleTimeString('en-US', {
timeZone: 'Asia/Tokyo',
hour: '2-digit',
minute: '2-digit',
second: '2-digit',
hour12: false // true = 12-hour, false = 24-hour
});
Key Date methods:
| Method | Description | Example |
|---|---|---|
new Date() | Create current timestamp | new Date() |
toLocaleTimeString() | Format time for specific locale/timezone | Returns "13:30:00" |
toLocaleDateString() | Format date for specific locale/timezone | Returns "Mar 12, 2026" |
getTime() | Get milliseconds since epoch | Returns 1750000000000 |
How to Use
Key Features
- All Timezones: Displays all ~440 IANA timezones supported by your browser
- Real-time Updates: Time updates every second automatically
- Searchable: Filter timezones by region, country, or city name
- Date & Offset: Shows local date and UTC offset for each timezone
You can search by:
| Search Type | Example | Result |
|---|---|---|
| Region | Asia | All Asian timezones (82 cities) |
| Region | Europe | All European timezones |
| Region | America | All American timezones |
| Country | China | Shanghai, Hong Kong, Macau, Urumqi |
| Country | USA | New York, Chicago, Los Angeles, Denver, etc. |
| City | London | Europe/London |
| City | Tokyo | Asia/Tokyo |
| City | New York | America/New_York |
Search Examples:
Asia→ All timezones starting withAsia/China→ Chinese timezones (Shanghai, Hong Kong, Macau, Urumqi)London→ Europe/LondonYork→ America/New_York, America/Yakutat
Browser Timezone Support
Different browsers may support different numbers of timezones. The number depends on:
- Browser version: Newer versions tend to support more timezones
- Operating System: The browser uses the OS's timezone database (IANA tzdb)
- Browser engine: Chrome, Firefox, Safari use different implementations
Approximate timezone counts by browser:
| Browser | Approximate Timezones |
|---|---|
| Chrome 120+ | ~440 |
| Firefox 120+ | ~430 |
| Safari 17+ | ~420 |
| Edge 120+ | ~440 |
The tool displays your browser's actual supported count at the top of the page.