Breviarium

Open source Liturgy of the Hours, collaborate to build the best Divine Office library!

Generates liturgical content and calendars of the Roman Rite of the Roman Catholic Church.
Supports Node v18+, Modern Browsers (desktop and mobile).

Quickstart setup

1. Install with your prefered package manager

npm install breviarium

pnpm install breviarium

yarn add breviarium

1. Import and use the library to retrieve the desired data (ex: Laudes) Usage:

const breviarium = new Breviarium(useDateStore().getCurrentDate);

// get laudes for today
await breviarium.getLaudes().then((data) => { console.log("laudes data:", data) })

const breviarium = new Breviarium(useDateStore().getCurrentDate);

// get laudes for a given date (example for 2025-7-30)
await breviarium.getLaudes(new Date(2025, 6, 30)).then((data) => { console.log("laudes data:", data) })

Function Documentation

Liturgy of the hours: functions to retrieve the information of the library:

Function	Parameters	Description	Example Call
getLaudes	date?: Date	Returns array (1): Laudes prayer for a given date.	prayers.getLaudes();
getVesperae	date?: Date	Returns array (1): the Vesperae prayer for a given date.	prayers.getVesperae(new Date(2025, 1, 17));
getOfficium	date?: Date	Returns the Officium prayer for a given date.	prayers.getOfficium();
getTertia	date?: Date	Returns the Tertia prayer for a given date.	prayers.getTertia();
getSexta	date?: Date	Returns the Sexta prayer for a given date.	prayers.getSexta(new Date());
getNona	date?: Date	Returns the Nona prayer for a given date.	prayers.getNona();
getCompletorium	date?: Date	Returns the Completorium prayer for a given date.	prayers.getCompletorium();
getLectures	date?: Date	Returns the Mass readings for a given date.	prayers.getLectures();
getEvangelium	date?: Date	Returns the Gospel text for a given date.	prayers.getEvangelium(new Date(2025, 5, 1));

(1): Some liturgical days, contains different options to pray: memory (example: a saint), and ferial (ordinary time). The Library displays both options and user can choose what version use.

Test

To run the test suite (with vitest), execute:

To run the app:

# linux and mac users:
make test
# for windows users:
npm run test

Changelog

See Changelog.md for breaking changes.

Debug

You can debug or see the libraries responses in: https://escribano.breviarium.es/debug select a day, the hour or prayer and display the JSON response

API Reference — Breviarium

Below is a comprehensive reference for the public API. Each function lists parameters, return type, and a compact output sample. All methods that accept a date?: Date will use the instance’s current date when omitted.

Construction & Date Utilities

• new Breviarium(selectedDate?: Date)

  • Parameters:
    • selectedDate?: Date — if omitted, today is used.
  • Returns: Breviarium

• setDate(date: Date): void

  • Parameters: date: Date
  • Returns: void

• getCurrentDate(): Date

  • Parameters: none
  • Returns: Date

Usage:

const breviarium = new Breviarium();
breviarium.setDate(new Date(2025, 6, 30));
console.log(breviarium.getCurrentDate());

Liturgy of the Hours — Core Retrieval Methods

• getInvitatorium(date?: Date): Promise<InvitatoriumSchemaOutput | undefined>

  • Returns: one Invitatorium entry or undefined if not available.
  • Output sample:

    {
      "id": "mary_mother_of_god",
      "val": "Antiphon and invitatory text..."
    }

• getLaudes(date?: Date): Promise<LaudesSchemaOutput[] | undefined>

  • Returns: array of Laudes options (some days have multiple options) or undefined.
  • Output sample:

    [{
      "id": "mary_mother_of_god",
      "cycle": "ANY",
      "himno": "Hymn text...",
      "primer_salmo_cita": "Ps 63",
      "primer_salmo_antifona": "Ant. ...",
      "primer_salmo_texto": "Psalm text...",
      "segundo_salmo_cita": "Cantico",
      "segundo_salmo_antifona": "Ant. ...",
      "segundo_salmo_texto": "...",
      "tercer_salmo_cita": "Ps 149",
      "tercer_salmo_antifona": "Ant. ...",
      "tercer_salmo_texto": "...",
      "lectura_biblica_cita": "1Th 5,16-18",
      "lectura_biblica": "Reading text...",
      "responsorios": ["V. ... R. ..."],
      "cantico_evangelico_antifona": "Ant. ...",
      "preces_intro": "Intro...",
      "preces_respuesta": "Resp...",
      "preces_contenido": ["Petition 1", "Petition 2"],
      "invitacion_padrenuestro": "Intro...",
      "oracion_final": "Collect text..."
    }]

• getVesperae(date?: Date): Promise<VesperaeSchemaOutput[] | undefined>

  • Returns: array of Vespers options or undefined.
  • Output sample:

    [{
      "id": "lent_5_monday",
      "cycle": "ANY",
      "primeras_visperas": false,
      "himno": "Hymn text...",
      "primer_salmo_cita": "Ps 110",
      "primer_salmo_antifona": "Ant. ...",
      "primer_salmo_texto": "...",
      "segundo_salmo_cita": "Ps 111",
      "segundo_salmo_antifona": "Ant. ...",
      "segundo_salmo_texto": "...",
      "tercer_salmo_cita": "Cantico",
      "tercer_salmo_antifona": "Ant. ...",
      "tercer_salmo_texto": "...",
      "lectura_biblica_cita": "Eph 1,3-10",
      "lectura_biblica": "Reading text...",
      "responsorios": ["V. ... R. ..."],
      "cantico_evangelico_antifona": "Ant. ...",
      "preces_intro": "Intro...",
      "preces_respuesta": "Resp...",
      "preces_contenido": ["Petition 1"],
      "invitacion_padrenuestro": "Intro...",
      "oracion_final": "Collect text..."
    }]

• getOfficium(date?: Date): Promise<OfficiumSchemaOutput | undefined>

  • Returns: Office of Readings object or undefined.
  • Output sample:

    {
      "id": "mary_mother_of_god",
      "cycle": "ANY",
      "himno": "Hymn text...",
      "primer_salmo_cita": "Ps ...",
      "primer_salmo_antifona": "Ant. ...",
      "primer_salmo_texto": "...",
      "segundo_salmo_cita": "Ps ...",
      "segundo_salmo_antifona": "Ant. ...",
      "segundo_salmo_texto": "...",
      "tercer_salmo_cita": "Ps ...",
      "tercer_salmo_antifona": "Ant. ...",
      "tercer_salmo_texto": "...",
      "lectura_biblica_titulo_a": "Title ...",
      "lectura_biblica_cita_a": "Ref ...",
      "lectura_biblica_texto_a": "Text ...",
      "lectura_patristica_titulo_a": "Title ...",
      "lectura_patristica_cita_a": "Ref ...",
      "lectura_patristica_texto_a": "Text ...",
      "responsorio1": ["V. ... R. ..."],
      "responsorio2_a": ["..."],
      "responsorio3_a": ["..."],
      "oracion_final": "Prayer text..."
    }

• getTertia(date?: Date): Promise<IntermediateSchemaOutput | undefined>

• getSexta(date?: Date): Promise<IntermediateSchemaOutput | undefined>

• getNona(date?: Date): Promise<IntermediateSchemaOutput | undefined>

  • Returns: Midday prayer object or undefined.
  • Output sample:

    {
      "id": "lent_2_monday",
      "cycle": "ANY",
      "himno": "Hymn text...",
      "primer_salmo_cita": "Ps ...",
      "primer_salmo_antifona": "Ant. ...",
      "primer_salmo_texto": "...",
      "segundo_salmo_cita": "Ps ...",
      "segundo_salmo_antifona": "Ant. ...",
      "segundo_salmo_texto": "...",
      "tercer_salmo_cita": "Ps ...",
      "tercer_salmo_antifona": "Ant. ...",
      "tercer_salmo_texto": "...",
      "lectura_biblica_cita": "Ref ...",
      "lectura_biblica": "Reading text...",
      "responsorios": ["V. ... R. ..."],
      "oracion_final": "Prayer text..."
    }

• getCompletorium(date?: Date): Promise<CompletoriumSchemaOutput | undefined>

  • Returns: Night Prayer object or undefined.
  • Output sample:

    {
      "idd": 4,
      "himno": "Hymn text...",
      "primer_salmo_cita": "Ps ...",
      "primer_salmo_antifona": "Ant. ...",
      "primer_salmo_texto": "...",
      "segundo_salmo_cita": "Ps ...",
      "segundo_salmo_antifona": "Ant. ...",
      "segundo_salmo_texto": "...",
      "lectura_biblica_cita": "Ref ...",
      "lectura_biblica_texto": "Reading text...",
      "responsorio": ["..."],
      "responsorio_pascua": ["..."],
      "antifona_triduo": "...",
      "antifona_inalbis": "...",
      "cantico_evangelico_antifona": "Ant. ...",
      "final": "Prayer text..."
    }

Mass Readings and Gospel

• getLectures(date?: Date): Promise<LecturesSchemaOutput[] | undefined>

  • Returns: array with the day’s readings sets or undefined.
  • Output sample:

    [{
      "id": "lent_5_monday",
      "cycle": "ANY",
      "lecturas": [
        { "ref": "Jer 14,17-22", "texto": "Reading text...", "type": "FIRSTLECTURE" },
        { "ref": "Ps 79", "texto": "Psalm text...", "type": "PSALM" },
        { "ref": "Mt 13,36-43", "texto": "Gospel text...", "type": "GOSPEL" }
      ]
    }]

• getEvangelium(date?: Date): Promise<EvangeliumSchemaOutput | undefined>

  • Returns: Gospel object (subset of lectures) or undefined.
  • Output sample:

    {
      "id": "mary_mother_of_god",
      "cycle": "ANY",
      "evangelium_lectiones": [
        { "ref": "Mt 13,36-43", "texto": "Gospel text...", "type": "GOSPEL" }
      ]
    }

Commons & Liturgy Info

• getInvitatoriumPsalms(): Promise<any[]>

  • Returns: list of invitatory psalms (Spanish content in current DB).
  • Output sample:

    [
      { "id": "psalm94", "title": "Salmo 94: Invitación a la alabanza divina", "psalm": "<p>Venid, aclamemos...</p>" },
      { "id": "psalm99", "title": "Salmo 99: Alegría de los que entran en el templo", "psalm": "<p>Aclama al Señor...</p>" }
    ]

• getLiturgyInformation(date?: Date): Promise<LiturgyInformationOutput>

  • Returns: metadata about the day: psalter week, cycle, color, celebration, etc. Always returns an object (with minimal defaults when unknown).
  • Output sample:

    {
      "psaltery_week": "I",
      "cycle": "A",
      "color": "GREEN",
      "color_hex": "#008000",
      "celebration": "Feria",
      "rank": "weekday",
      "seasons": ["ORDINARY_TIME"],
      "precedence": "weekday",
      "periods": ["ORDINARY_TIME"],
      "calendar": { "endOfLiturgycalSeason": "2025-11-29" }
    }