Timezone Data

This repository maintains timezone database files used by piCorePlayer to convert IANA/Olson timezone identifiers to Linux TZ format strings.

Automatic Updates

The timezones.db file is automatically updated from IANA timezone data via a GitHub Action workflow:

• Manual Trigger: The workflow can be manually triggered from the Actions tab
• Scheduled: Runs automatically every Monday at 00:00 UTC
• Branch: Updates are committed directly to the gh-pages branch

Files

• update_timezones.py: Python script that downloads the latest IANA timezone data and generates timezones.db
• .github/workflows/update-timezones.yml: GitHub Action workflow that runs the update script
• timezones.db: The generated timezone database (located in gh-pages branch)

How it Works

1. Downloads the latest timezone data from https://data.iana.org/time-zones/releases/tzdata-latest.tar.gz
2. Checks the version of the downloaded data against the existing timezones.db file
3. If the version is the same, exits early (no update needed)
4. If the version is different, extracts and compiles the timezone files using the zic tool
5. Parses the compiled timezone files to extract Linux TZ format strings
6. Generates timezones.db with mappings from timezone names to TZ strings
7. Validates the generated file has the expected format and content
8. Commits changes to the gh-pages branch if the file has been updated

Format

The timezones.db file contains:

• A header comment indicating the IANA tzdata version and build date
• One timezone per line in the format: Timezone/Name TZ_STRING

Example:

# This file is based on iana.org tzdata 2025c built on 2025-12-19 00:35:20 UTC
Africa/Abidjan GMT0
Africa/Accra GMT0
America/New_York EST5EDT,M3.2.0,M11.1.0

Usage

The generated timezones.db file is hosted via GitHub Pages and accessed by the timezone-worker Cloudflare Worker to provide timezone conversions.