caldays vs UK Bank Holidays

Caldays provides free public holiday data for 206 countries in JSON format, plus long-weekend calculations and a world clock endpoint. Anonymous use is capped at 10,000 requests per day; a metered API key raises the limit for higher-volume needs. The holiday data carries a CC BY 4.0 licence, so users must credit Caldays in their app.

The UK government publishes England & Wales, Scotland, and Northern Ireland bank holidays as a single static JSON file at gov.uk, listing each holiday's date, title, and whether it's a “substitute day” moved from a weekend. It's official, authoritative, and requires nothing beyond an HTTP GET — no key, no rate limit, and it's licensed under the Open Government Licence for reuse including commercially.