Catholic Liturgical Calendar
API /calendar endpoint
Collection of Liturgical events for any given year between 1970 and 9999. The base /calendar path returns liturgical events for the General Roman Calendar. National and Diocesan calendars can be requested on the /calendar/nation/{NATION} and /calendar/diocese/{DIOCESE} paths respectively. Each of these paths can optionally be further specified with a /{YEAR} path parameter. When not specified, the API will default to the current year.
Path builder
Request parameters available on the base /calendar path
/calendar/nation/{NATION} and /calendar/diocese/{DIOCESE} routes. N.B. When none of these parameters are set, the API will use the defaults as in use in the Vatican.
Request parameters available on all /calendar paths
/calendar resource or any resource below the /calendar path. National and Diocesan calendars do not have these parameters built-in.
https://litcal.johnromanodorazio.com/api/v3/calendar
Liturgical Calendar Validator
Translation Tool
Translations status
Open API Schema
All of the available API routes with their supported methods, parameters, content types and responses are described here.
Calculation of the Date of Easter: API
A simple API endpoint that returns data about the Date of Easter, both Gregorian and Julian, from 1583 (year of the adoption of the Gregorian Calendar) to 9999 (maximum possible date calculation in 64bit PHP), using a PHP adaptation of the Meeus/Jones/Butcher algorithm for Gregorian easter (observed by the Roman Catholic church) and of the Meeus algorithm for Julian easter (observed by orthodox churches).
Currently the data can be requested with almost any localization. In any case, since the API returns a UNIX timestamp for each date of Easter, localizations can be done in a client application just as well.