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// find IANA timezone identifiers instantly
Look up IANA timezone identifiers for any country or city. Find UTC offsets, DST status, and timezone names for developers and system admins.
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Type a country, city, or partial timezone name in the search box.
Use the region buttons to narrow down to a specific continent.
Click any timezone card to see details, then copy the IANA ID or code snippets.
Intl.DateTimeFormat optionspytz / zoneinfo lookupsAT TIME ZONE queriesThis tool lets you find the official IANA timezone identifier for any location. IANA IDs (like America/New_York) are the standard used in programming languages, databases, and operating systems to represent timezones accurately — including daylight saving transitions.
An IANA timezone identifier is a standardized string like America/New_York or Asia/Tokyo that uniquely names a timezone region. They are maintained by the Internet Assigned Numbers Authority (IANA) and used globally in programming languages, operating systems, and databases to handle timezone conversions including daylight saving time transitions.
UTC offsets like UTC+5 don't account for daylight saving time changes. When a region observes DST, its UTC offset shifts by 1 hour. IANA IDs encode the full historical and future schedule of timezone transitions, making them far more reliable for applications that need accurate time across different seasons.
Use the Intl.DateTimeFormat API or toLocaleString: new Date().toLocaleString("en-US", { timeZone: "America/Los_Angeles" }). For more control, libraries like date-fns-tz or Luxon accept IANA identifiers directly.
Run timedatectl set-timezone America/New_York (replace with your IANA ID). Or symlink the zoneinfo file: ln -sf /usr/share/zoneinfo/America/New_York /etc/localtime. You can also set the TZ environment variable in your shell profile or Docker container.
In Python 3.9+, use the built-in zoneinfo module: from zoneinfo import ZoneInfo; ZoneInfo("Europe/London"). For older versions, use pytz: import pytz; tz = pytz.timezone("Europe/London"). Both accept standard IANA identifiers.
UTC (Coordinated Universal Time) and GMT (Greenwich Mean Time) are nearly identical in practice and share the same offset (+00:00). The key difference is technical: UTC is an atomic time standard used as the primary reference, while GMT is a timezone that observes no DST. In programming, prefer UTC as the standard reference.
The IANA Time Zone Database currently contains around 590–600 named timezone identifiers, though many are aliases of others. The database is updated regularly to reflect changes made by governments — countries occasionally shift timezone boundaries, adopt or abandon DST, or change UTC offsets.
For countries like the United States, Russia, or Australia that span multiple timezones, you'll need the specific region. The US alone has zones like America/New_York, America/Chicago, America/Denver, and America/Los_Angeles. Use this tool to search by city name to find the correct identifier for a specific location.
A Timezone Name Lookup tool helps developers, system administrators, and anyone working across time zones find the correct IANA timezone identifier for any country, city, or region. Rather than memorizing strings like America/Los_Angeles or Asia/Kolkata, you can simply search by location and instantly retrieve the standardized timezone name, current UTC offset, and DST status.
This tool draws from the complete IANA Time Zone Database — the authoritative source used by Unix-like operating systems, programming languages, and databases worldwide to handle time zone conversions accurately.
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When building applications that serve users across different regions, handling time correctly is one of the most error-prone challenges in software development. A common mistake is storing or computing times using abbreviated timezone names like EST, PST, or IST. These abbreviations are ambiguous — IST, for example, can mean Indian Standard Time, Irish Standard Time, or Israel Standard Time depending on context.
IANA identifiers eliminate this ambiguity entirely. Each identifier maps to a specific geographic region with a well-defined history of UTC offsets and daylight saving time transitions. Using Asia/Kolkata instead of IST+5:30 ensures your application correctly handles edge cases like DST changes without any extra logic.
IANA timezone identifiers follow a hierarchical naming convention: Continent/City. The continent portion is one of Africa, America, Antarctica, Asia, Atlantic, Australia, Europe, Indian, or Pacific. The city portion typically refers to a major city in that timezone region — not necessarily the capital, but often a well-known population center that represents that offset.
For example, the US Eastern timezone is identified as America/New_York, covering the eastern seaboard from Maine down to Florida, all sharing the same DST schedule. The UK uses Europe/London, which switches between GMT (+00:00) in winter and BST (+01:00) in summer.
JavaScript: The built-in Intl API fully supports IANA identifiers. Use new Intl.DateTimeFormat('en-US', { timeZone: 'America/Chicago' }) to format dates, or pass the timezone to toLocaleString. Libraries like Luxon and date-fns-tz also accept IANA identifiers natively.
Python: Python 3.9 introduced the zoneinfo standard library module which accepts IANA identifiers directly via ZoneInfo("Europe/Berlin"). The third-party pytz library works similarly for older Python versions.
PHP: PHP's DateTimeZone class accepts IANA identifiers: new DateTimeZone('Asia/Tokyo'). The full list is available via DateTimeZone::listIdentifiers().
SQL Databases: PostgreSQL supports AT TIME ZONE 'America/Denver' syntax in queries. MySQL and MariaDB require timezone tables to be populated via mysql_tzinfo_to_sql, after which you can use CONVERT_TZ() with IANA identifiers.
On Linux systems, the timezone is configured via the /etc/localtime symlink pointing to a file in /usr/share/zoneinfo/. Modern systems use timedatectl set-timezone America/New_York via systemd. In Docker, set the TZ environment variable in your Dockerfile or docker-compose.yml: TZ=Europe/Amsterdam.
For Node.js applications, the TZ environment variable also controls the process timezone. This is especially useful in serverless environments where you want consistent timezone behavior regardless of the host system's settings.
Daylight Saving Time (DST) is observed by roughly 70 countries, each with its own rules for when clocks change and by how much. The IANA database encodes all known historical and current DST transitions for every timezone. This means that when you use America/New_York, your programming language automatically knows that clocks spring forward one hour on the second Sunday of March and fall back on the first Sunday of November.
This database gets updated several times per year as governments announce changes. Countries like Samoa, Russia, and Turkey have historically made significant timezone changes, and the IANA database tracks all of these adjustments. Always use the latest version of your language runtime or timezone library to ensure you have current DST data.