Church Calendar vs UK Bank Holidays

Church Calendar (calapi) serves the daily Roman Catholic liturgical calendar — season, week, feast rank, and liturgical color — for a given date and country-specific calendar variant, in English, Czech, Latin, or Spanish. It's a small keyless JSON API maintained by a Czech developer alongside the printed liturgical calendars he publishes. There's no pricing or account system of any kind; the only quirk is that its real backend still only serves plain HTTP, timing out on HTTPS.

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.