coptic-readings

Given a date, get the Coptic Orthodox liturgical reading references for that day — Psalms, Gospels, Pauline, Catholic, Acts, and (in Lent) prophecies — plus feast, tune, and Coptic calendar context.

This package returns Bible references (e.g. John 20:1-18). Turning those into verse text is left to your Bible source of choice.

Install

npm install coptic-readings

Works with ESM, CommonJS, and TypeScript.

What reading books are used?

The Coptic Church uses different Katamaros books depending on the season. This package picks the right one for each day:

| Season | Source | When it’s used | | --- | --- | --- | | Annual Katamaros (weekdays) | Daily readings for each Coptic month/day | Ordinary weekdays outside special seasons | | Sunday Katamaros | Readings for the 1st–5th Sunday of each Coptic month | Sundays in the annual cycle | | Great Lent Katamaros | Lent weekday & Holy Week readings | Jonah Fast, Great Lent, and Palm Sunday (Hosanna) | | Holy Fifty Katamaros | Readings from Resurrection through Pentecost | The 50 days from Easter to Pentecost |

You don’t need to choose the book yourself — pass a date and the library selects the matching season.

Quick start

import { CopticReadings } from 'coptic-readings'

const day = new CopticReadings(new Date(2026, 3, 12)) // 12 Apr 2026

console.log(day.feast)
// { name: 'resurrection', tune: 'joy', katamaros: 'holy_fifties' }

console.log(day.readingReference.ref?.liturgy)
// {
//   pauline: '1 Corinthians 15:23-50',
//   catholic: '1 Peter 3:15-4:6',
//   acts: 'Acts 2:22-28',
//   psalm: 'Psalms 118:24,25,27',           // MT — Bible text lookup
//   psalm_coptic_ref: 'Psalms 117:24,25,27', // LXX/Coptic — display
//   gospel: 'John 20:1-18'
// }

Psalm fields ship as a pair wherever a psalm is present:

| Field | Numbering | Use | | --- | --- | --- | | psalm | Masoretic (NKJV) | Resolve verse text (bible-citation-text, etc.) | | psalm_coptic_ref | Septuagint / Coptic | Show the liturgical citation to users |

Helpers mtPsalmToCopticRef, mtToLxxChapter, and lxxToMtChapter are exported if you need the same mapping elsewhere.

CommonJS

const { CopticReadings } = require('coptic-readings')

TypeScript

import { CopticReadings, type DayReadings, type ActiveFeast } from 'coptic-readings'

const day = new CopticReadings(new Date(2026, 3, 12))
const feast: ActiveFeast = day.feast
const ref: DayReadings | null | undefined = day.readingReference.ref

Describe a liturgical day

A small helper that gathers the useful fields in one place:

import { CopticReadings } from 'coptic-readings'

function formatYmd(d) {
  const y = d.getFullYear()
  const m = String(d.getMonth() + 1).padStart(2, '0')
  const day = String(d.getDate()).padStart(2, '0')
  return `${y}-${m}-${day}`
}

function describeLiturgicalDay(date, options = {}) {
  const day = new CopticReadings(date, {
    // Pin clock so evening (≥ 18:00) does not shift the day in daytime examples
    now: options.now ?? new Date(date.getFullYear(), date.getMonth(), date.getDate(), 10),
    ...options,
  })
  const { ref, isSunday } = day.readingReference

  return {
    date: formatYmd(date),
    effectiveLiturgicalDay: formatYmd(day.effectiveLiturgicalDay),
    copticDate: day.copticDate,
    copticMonth: day.copticMonth,
    copticDay: day.copticDay,
    weekday: day.weekday,
    adamOrWatos: day.adamOrWatos,
    isSunday: day.isSunday,
    feast: day.feast,
    readingReference: {
      isSunday,
      ref: ref
        ? {
            title: ref.title ?? null,
            vespers: ref.vespers ?? null,
            matins: ref.matins ?? null,
            liturgy: ref.liturgy ?? null,
            evening: ref.evening ?? null,
          }
        : null,
    },
  }
}

console.log(JSON.stringify(describeLiturgicalDay(new Date(2026, 3, 12)), null, 2))

Resurrection Sunday — 2026-04-12

Uses the Holy Fifty Katamaros:

{
  "date": "2026-04-12",
  "effectiveLiturgicalDay": "2026-04-12",
  "copticDate": "04/08/1742",
  "copticMonth": "Baramouda",
  "copticDay": 4,
  "weekday": "Sunday",
  "adamOrWatos": "adam",
  "isSunday": true,
  "feast": {
    "name": "resurrection",
    "tune": "joy",
    "katamaros": "holy_fifties"
  },
  "readingReference": {
    "isSunday": true,
    "ref": {
      "title": "Glorious Resurrection Sunday",
      "vespers": null,
      "matins": {
        "psalm": "Psalms 77:56;Psalms 77:60",
        "gospel": "Mark 16:2-11"
      },
      "liturgy": {
        "pauline": "1 Corinthians 15:23-50",
        "catholic": "1 Peter 3:15-4:6",
        "acts": "Acts 2:22-28",
        "psalm": "Psalms 117:12-25",
        "gospel": "John 20:1-18"
      },
      "evening": null
    }
  }
}

Great Lent weekday — 2026-02-23

Uses the Great Lent Katamaros (includes Old Testament prophecies at liturgy):

describeLiturgicalDay(new Date(2026, 1, 23))

{
  "date": "2026-02-23",
  "feast": { "name": "great_lent", "tune": "fasting", "katamaros": "great_lent" },
  "readingReference": {
    "ref": {
      "title": "Monday of the second week of Great Lent",
      "matins": { "psalm": "Psalms 38:11", "gospel": "Mark 9:25-29" },
      "liturgy": {
        "prophecies": ["Exodus 3:6-14", "Isaiah 4:2-5:7"],
        "pauline": "Romans 1:18-25",
        "catholic": "Jude 1:1-8",
        "acts": "Acts 4:36-5:11",
        "psalm": "Psalms 28:1-2",
        "gospel": "Luke 18:1-8"
      }
    }
  }
}

Jonah Fast — 2026-02-02

Also draws from the Great Lent Katamaros:

describeLiturgicalDay(new Date(2026, 1, 2))
// feast.name === "jonah_fast"
// ref.title === "Monday of Jonah's Fast"
// liturgy.prophecies === ["Jonah 1:1-2:1"]

Pentecost — 2026-05-31

Last day of the Holy Fifty:

describeLiturgicalDay(new Date(2026, 4, 31))
// feast.name === "pentecost"
// ref.title === "Seventh Sunday of the Holy Fifty (Feast of Pentecost)"

Ordinary annual day — 2026-07-18

Annual Katamaros weekday readings:

describeLiturgicalDay(new Date(2026, 6, 18))
// feast: { name: null, tune: "annual", katamaros: "annual" }
// liturgy.gospel === "Luke 12:4-12"

After 6pm — next liturgical day

In Coptic practice, the liturgical day often begins in the evening. By default, after 18:00 the package treats the date as the next calendar day:

const evening = new Date(2026, 3, 11, 19) // Sat 11 Apr 2026, 19:00
describeLiturgicalDay(new Date(2026, 3, 11), { now: evening })
// effectiveLiturgicalDay → "2026-04-12" (Resurrection Sunday)

You can change the hour with liturgicalDayStartsAtHour, or pass now to control the clock used for that check.

Orthodox Easter dates for a year

Need the movable-season anchors (Jonah Fast, Great Lent, Palm Sunday, Easter, Pentecost, Apostles’ Fast)?

import { calculateOrthodoxEaster } from 'coptic-readings'

function formatYmd(d) {
  const y = d.getFullYear()
  const m = String(d.getMonth() + 1).padStart(2, '0')
  const day = String(d.getDate()).padStart(2, '0')
  return `${y}-${m}-${day}`
}

function describePaschalYear(year) {
  const s = calculateOrthodoxEaster(year)
  return {
    year,
    jonah_fast: {
      start: formatYmd(s.startfJonahFast),
      end: formatYmd(s.endfJonahFast),
      feast: formatYmd(s.jonahFeast),
    },
    great_lent: {
      start: formatYmd(s.startOfGreatLent),
      end: formatYmd(s.endOfGreatLent),
    },
    hosanna: formatYmd(s.hosannaDate),
    resurrection: formatYmd(s.easterDate),
    pentecost: formatYmd(s.pentecosteDate),
    apostles_fast_start: formatYmd(s.apostolesFastStartDate),
  }
}

console.log(JSON.stringify(describePaschalYear(2026), null, 2))

Example — 2026

{
  "year": 2026,
  "jonah_fast": {
    "start": "2026-02-02",
    "end": "2026-02-04",
    "feast": "2026-02-05"
  },
  "great_lent": {
    "start": "2026-02-16",
    "end": "2026-04-04"
  },
  "hosanna": "2026-04-05",
  "resurrection": "2026-04-12",
  "pentecost": "2026-05-31",
  "apostles_fast_start": "2026-06-01"
}

| Milestone | 2026 date | | --- | --- | | Jonah Fast | 2–4 Feb (feast 5 Feb) | | Great Lent | 16 Feb – 4 Apr | | Hosanna (Palm Sunday) | 5 Apr | | Resurrection | 12 Apr | | Pentecost | 31 May | | Apostles’ Fast begins | 1 Jun |

API summary

new CopticReadings(date?, options?)

| Option | Default | Description | | --- | --- | --- | | now | new Date() | Clock used for the evening liturgical-day rollover | | liturgicalDayStartsAtHour | 18 | Hour when the next liturgical day begins |

| Getter | Description | | --- | --- | | readingReference | { isSunday, ref } — vespers / matins / liturgy (/ evening) Bible refs | | feast | { name, tune, katamaros } — active feast (name is null on ordinary days) | | copticDate / copticMonth / copticDay | Coptic calendar for the liturgical day | | weekday / adamOrWatos / isSunday | Weekday helpers | | daysFromEaster | Days relative to Resurrection (0 = Easter Sunday) | | effectiveLiturgicalDay | Calendar date after applying the evening rollover | | all | Full feast map for the year |

calculateOrthodoxEaster(year)

Returns { easterDate, hosannaDate, pentecosteDate, apostolesFastStartDate, startOfGreatLent, endOfGreatLent, startfJonahFast, endfJonahFast, jonahFeast }.