@bgonzalezbustamante/catholic-calendar

A small, UI-agnostic TypeScript engine for the curated Roman Catholic calendar model used by the Catholic Calendar project.

Install

npm install @bgonzalezbustamante/catholic-calendar

Usage

import {
  getCatholicCalendarState,
  getCalendarDisplaySummary,
} from '@bgonzalezbustamante/catholic-calendar'

const state = getCatholicCalendarState('2026-09-08')
const display = getCalendarDisplaySummary(state)

console.log(display.text)
// Nativity of the Blessed Virgin Mary · St Michael's Lent

The package exposes the same engine used by the demonstration application, including computus helpers, selected observances, periods, calendar-state resolution, Year Overview data and compact display summaries.

Scope

• Supported civil years: 2000–2100.
• Uses universal Roman dates for Epiphany, Ascension and Corpus Christi.
• Models a curated observance set rather than a complete General Roman Calendar or local proper calendar.
• Models Christmas Time, Lent, Holy Week, the Sacred Paschal Triduum, Easter Time and Advent.
• Models St Michael’s Lent separately as a devotional period.
• Ordinary Time is intentionally not modelled.
• commemoration-eligible means a memorial may be commemorated while the privileged seasonal weekday retains liturgical precedence.

See the repository README and docs/SOURCES.md for the full scope, sources and rule limitations.

Licence

MIT. See LICENSE.