tzif-data

Automatically build and publish compiled IANA time zone data files in TZif (zoneinfo) format.

This repository provides static URLs for downloading individual compiled time zone files, for example:

• https://nicolasbon.net/tzif-data/zoneinfo/Europe/Amsterdam
• https://nicolasbon.net/tzif-data/zoneinfo/America/New_York
• https://nicolasbon.net/tzif-data/zoneinfo/Etc/UTC

What this repository does

The GitHub Actions workflow:

1. Downloads the latest IANA tzdata archive.
2. Extracts the time zone source files.
3. Compiles them with zic into binary TZif files.
4. Copies the compiled zoneinfo tree into a GitHub Pages artifact.
5. Deploys the files to GitHub Pages.

The generated files are suitable for software that can read standard TZif files.

Why

Some environments, especially embedded systems, browsers, static clients, or small custom runtimes, may not have a local /usr/share/zoneinfo database available.

This project makes it possible to fetch a compiled time zone file directly over HTTP from a static host.

Data source

The data comes from the IANA Time Zone Database, also known as tz or zoneinfo.

IANA publishes time zone rules and historical offset data for representative locations around the world. The database is updated periodically when political bodies change UTC offsets, daylight-saving rules, or time zone boundaries.

Notes

• This repository does not define time zone rules itself.
• It republishes compiled output from the upstream IANA time zone database.
• Consumers should treat the generated files as data files, not as an API with stability guarantees beyond the normal IANA zone names and aliases.
• If exact reproducibility matters, pin to a specific generated commit rather than relying on the latest deployment.

License

This repository’s workflow and documentation are dedicated to the public domain under CC0-1.0.

The generated TZif files are compiled from the IANA Time Zone Database. The upstream tzdb data is public domain unless otherwise specified by IANA.