Every IANA timezone identifier from the tz database with its current UTC offset, common abbreviation, and daylight saving time status. This is the authoritative reference used by operating systems, programming languages, and databases worldwide to handle time conversion accurately.
Pro tip: Always store the IANA identifier (e.g. America/New_York) rather than a fixed UTC offset — the identifier automatically handles daylight saving time transitions in your datetime library.
Select which columns to include in your download.
About the IANA Timezones Dataset
This dataset contains every timezone identifier maintained in the IANA Time Zone Database (also known as the tz database or Olson database). Each entry includes the canonical timezone name, its current standard UTC offset, the common abbreviation, and whether daylight saving time is currently observed. The tz database is the definitive source used by Linux, macOS, Java, PHP, Python, JavaScript, and virtually every modern platform for timezone handling.
Common Use Cases
Timezone reference data is fundamental to any application that operates across geographic boundaries:
- Timezone selector dropdowns: Populate user preferences and registration forms with a complete, correctly formatted list of timezone options that map directly to your backend datetime library.
- Meeting schedulers: Convert proposed meeting times between participants in different timezones by looking up the UTC offset for each timezone identifier.
- Log normalization: Convert timestamps from distributed systems across multiple timezones into a single UTC reference using the offset data in this dataset.
- Display formatting: Show users the correct timezone abbreviation (EST, PST, CET) alongside timestamps in your application interface.
Column Reference
Each timezone record includes the following fields:
- timezone_id — The canonical IANA timezone identifier in
Area/Locationformat (e.g.America/New_York,Europe/London,Asia/Tokyo). - utc_offset — The current standard UTC offset expressed as
+HH:MMor-HH:MM(e.g.-05:00,+09:00). - abbreviation — The commonly used timezone abbreviation (e.g.
EST,JST,CET). Note that some abbreviations are ambiguous and shared across timezones. - dst — Whether the timezone currently observes daylight saving time (
yesorno).
Daylight Saving Time Considerations
UTC offsets change for timezones that observe daylight saving time. The offset in this dataset reflects the current standard offset at the time of export. For applications that need to handle DST transitions correctly, always use the IANA timezone identifier with your programming language's native datetime library rather than hardcoding the UTC offset. Libraries like moment-timezone in JavaScript, pytz in Python, and DateTimeZone in PHP all accept IANA identifiers and automatically apply the correct offset for any given date and time, including historical rule changes.
Timezone Identifier Best Practices
When storing timezone preferences in your database, always use the full IANA identifier rather than an abbreviation or fixed offset. Abbreviations like CST are ambiguous — they could refer to Central Standard Time in the US, China Standard Time, or Cuba Standard Time. Fixed offsets like UTC-6 do not account for daylight saving time changes. The IANA identifier is the only representation that unambiguously identifies a timezone and its complete set of historical and future offset rules. Store it as a VARCHAR(64) column and validate user input against this dataset before saving.