Japanese holiday function and official reference
Source: Cabinet Office, 国民の祝日について.
- CSV: https://www8.cao.go.jp/chosei/shukujitsu/syukujitsu.csv
- Retrieved: 2026-10-28
- Original SHA-256:
cec37a743c96995cdb9cb52b685c9003634682a9b0e1a640a6b9b96881fe964a - Coverage: 1955-01-01 through 2027-11-23
- Conversion: CP932 to UTF-8; dates normalized to YYYY-MM-DD; header removed.
japanese-holidays.rhai is the editable, built-in runtime data source. It calculates 1955–2099 Japanese holidays, including historical rules and one-off exceptions. Unpublished years are estimates; equinox holidays become official after publication in the government gazette. See NAOJ.
The CSV is an independent regression reference, including substitute holidays and holidays between national holidays. The full function output is checked against every date and name for 1955–2027. To refresh the reference, download the official CSV, apply the same conversion, update exceptions in the function as needed, and rerun calendar tests.
Source terms: Cabinet Office website terms.