Generate Time-Zone Data

generate-time-zone-data builds the compact IANA time-zone database and Windows mapping from the checked-in tzdb 2026b and CLDR 48 snapshots under tool/data/time_zone. Run it after changing those snapshots or the generator.

Check or Regenerate

Run from the repository root with the tool built from the current checkout:

./erbsland-core-tool generate-time-zone-data --check
./erbsland-core-tool generate-time-zone-data

The command writes the region factories, text and rule tables, zone dispatch, database version, and Windows mapping in src/erbsland/time/tz/impl. --check (-c) reports missing or stale files without writing. Review zone IDs, transitions, abbreviations, and CLDR mappings, then run the affected time tests.

Configuration

tool/conf/tools/generate_time_zone_data.elcl sets output_directory. Use --output-directory (-o) for a one-off comparison in an existing project directory. tool/conf/source/time_zone.elcl selects the source directory. The source manifest pins both releases and exact file hashes. See Time-Zone Generator Reference for the input and representation contracts; see Run and Configure Commands for shared tool options.