Church Calendar vs Non-Working Days

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.

icsdb is an open-data repository of pre-built .ics calendar files enumerating official non-working days for France (and its overseas territories), Belgium, Germany, Ireland, Switzerland, the UK's home nations, and the US, maintained on GitHub rather than served through a query API. Consumers fetch the raw .ics files directly off raw.githubusercontent.com (which serves them with open CORS) and import them into any calendar tool or icalendar-parsing library; there's no key, rate limit, or cost, but the project itself has had no commits since 2020.