Timezone Reference & World Clock
Search and browse all IANA timezones with live current times, UTC offsets, and DST indicators.
About This Tool
The Timezone Reference & World Clock is a comprehensive browser-based tool that lets developers and anyone working across time zones browse the complete IANA timezone database. Every recognized timezone is listed with its current local time, UTC offset, abbreviation, and daylight saving time (DST) status, all updating in real time.
All processing happens entirely in your browser using the built-in
Intl.DateTimeFormat API. No data is sent to any server. This makes
it safe to use on any network and ensures the fastest possible
response times.
You can search by city name, timezone ID (e.g., America/New_York),
or abbreviation (e.g., EST, JST). Filter by region to narrow
the list to Africa, Americas, Asia, Europe, Pacific, or other groups.
The group-by-offset mode clusters timezones that share the same UTC
offset, which is particularly useful when looking for alternatives in
a given offset band.
The built-in comparison feature lets you select any two timezones and instantly see the offset difference between them, along with both current times. This is invaluable when scheduling meetings across continents or converting deadlines between offices.
Timezones that are currently observing daylight saving time are highlighted with a DST badge. This gives you an at-a-glance view of which regions have shifted their clocks, helping you avoid off-by-one-hour mistakes in scheduling and timestamp calculations.
If you work with Unix timestamps, pair this tool with the Timestamp Converter to convert between epochs and human-readable dates with timezone awareness. For scheduling recurring tasks, the Cron Expression Builder can help you build schedules that account for timezone differences. Developers building internationalized applications may also find the Timezone Converter & World Clock useful for side-by-side time comparisons.
How to Use
- Open the tool and browse the full list of IANA timezones sorted by UTC offset.
- Use the search box to filter by city name, timezone ID, or abbreviation (e.g., type "Tokyo", "America/Chicago", or "CET").
- Select a region from the dropdown to show only timezones in that geographic area.
- Click Group by Offset to cluster timezones that share the same UTC offset.
- Click any timezone ID to copy it to your clipboard for use in code or configurations.
- Click Compare to open the comparison panel, then select two timezones to see the offset difference and both current times.
- Timezones with a yellow DST badge are currently observing daylight saving time.
- Use the keyboard shortcut Ctrl+Shift+C to copy all visible timezone IDs.
Timezone Reference Guides
FAQ
Is my data safe when using this tool?
Yes. This tool runs entirely in your browser using the built-in Intl.DateTimeFormat API. No data is sent to any server, no cookies are set, and nothing is logged.
Where does the timezone data come from?
The tool uses the IANA timezone database embedded in your browser via the Intl.supportedValuesOf('timeZone') API. This is the same database used by operating systems and programming languages worldwide to handle time zone conversions.
How is daylight saving time (DST) detected?
The tool compares the UTC offset of each timezone in January and July. If the offsets differ, the timezone observes DST. The current offset is then compared to determine if DST is currently active. This is done entirely client-side using Intl.DateTimeFormat.
What is the difference between a timezone offset and a timezone ID?
A timezone offset like UTC+05:30 describes a fixed difference from UTC at a specific moment. A timezone ID like Asia/Kolkata describes a geographic region with its full history of offset changes, including DST transitions. Always use timezone IDs in code, as offsets can change.
Do all timezones have whole-hour offsets?
No. Several timezones use half-hour offsets (e.g., Asia/Kolkata at UTC+05:30, Australia/Adelaide at UTC+09:30) and some even use 45-minute offsets (e.g., Asia/Kathmandu at UTC+05:45, Pacific/Chatham at UTC+12:45).
How often does the timezone list update?
The IANA timezone database is maintained by a global community and is updated several times per year as countries change their timezone rules. Your browser receives these updates through OS and browser updates.
Can I use this tool to find the best meeting time across timezones?
Yes. Use the comparison feature to see the offset between two timezones, then check the current times to find overlapping working hours. For more advanced scheduling, try the Timezone Converter & World Clock tool.
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