How Scripture Readings system works?

[JurisPrudens]

I am sorry for this very basic question.
What is the system for the Mass Readings? I know that weekday Masses follow one cycle, Sunday Masses follow a different one. I know there are A, B and C years.
Which Church act/document governs the Mass readings?

 

[Usige]

Essentially there are a couple elements that govern the readings.

The first is the liturgical calendar. It defines where you are in the liturgical year as well as the days for solemnities, memorials and feasts. Based on where you are in the liturgical calendar defines what set of readings are used for a given day (i.e. Sunday of the 24th week of ordinary time vs Wednesday of the 2nd week of Advent).

For Sundays there is a 3 year cycle made up of Years A, B, and C.
For weekdays there is a 2 year cycle made up of Years 1 and 2.
Feasts and memorials may or may not have specific readings. To the best of my knowledge, solemnities always do.

There are rules of precedent on what reading is higher in priority when a solemnity falls during different parts of the calendar, but I’d have to go look them up for specifics.

As far as I know the cycle and associated readings where promulgated by Pope Paul VI when establishing the current order of the mass.

 

[Todd977]

Yes. The Sunday readings are on a 3-year cycle. During the first year of readings, Year A, the Gospel Reading for each Sunday is mostly taken from Matthew; during the second year of readings, Year B, it is mostly taken from Mark; during the third year of readings, Year C, it is mostly taken from Luke. Year B follows Year A; Year C follows Year B; Year A follows Year C. A new year of readings begins on the First Sunday of Advent which depending on the year is either the last Sunday of November or the first Sunday of December.

The Weekday readings are on a 2-year cycle. Year II follows Year I; Year I follows Year II. Year I readings in odd-numbered years (2015, 2017, 2019, etc.); Year II readings in even-numbered years (2014, 2016, 2018, etc.)

For example:
Dec 2013 through 2014: Sundays, Year A; Weekdays, Year II.
Nov 2014 through 2015: Sundays, Year B; Weekdays, Year I.
Nov 2015 through 2016: Sundays, Year C; Weekdays, Year II. ← current year.
Nov 2016 through 2017: Sundays, Year A; Weekdays, Year I.
Dec 2017 through 2018: Sundays, Year B; Weekdays, Year II.
Dec 2018 through 2019. Sundays, Year C; Weekdays, Year I.

It is my understanding that the readings are set forth in the *Missale Romanum *(Roman Missal), promulgated by the pope.

 

[John_Lilburne]

The main book that gives the readings in the Lectionary. The Latin edition of this is Ordo Lectionum Missae, published in 1981. From its list of the readings various countries Conferences of Bishops publish lectionaries.

As new saints are canonised there can be new readings for their feast day.

The Roman Missal has instructions about readings.

The Book of Blessings has in “Order for the Blessing of a New Lectern” when this is done in the Mass:

“1177 The readings are either those assigned for the Mass of the day, or the following texts may be chosen: first reading: Nehemiah 8:1-4a, 5-6, 8-10, followed by …”.

In the Latin edition of this liturgical book this is in n. 904.

The 1974 Directory for Masses with Children includes: “43. If all the readings assigned to the day seem to be unsuited to the capacity of the children, it is permissible to choose readings or a reading either from the Lectionary of the Roman Missal or directly from the Bible, but taking into account liturgical seasons.”

The 1969 Instruction Actio Pastoralis on Masses with Special Groups has: “6 … e. In the liturgy of the word, depending on the actual situation, texts may be chosen that are more suited to the particular celebration, provided they are chosen from the texts of an approved lectionary.” There is a similar instruction in the General Instruction of the Roman Missal, n. 358.

Here are some extracts from the General Instruction of the Roman Missal:

“362. In addition to the options noted above for choosing certain more suitable texts, the Conference of Bishops has the faculty, in particular circumstances, to indicate some adaptations as regards readings, provided that the texts are chosen from a duly approved Lectionary.”

Regarding the Responsorial Psalm it has. “61. … Instead of the Psalm assigned in the Lectionary, there may be sung either the Responsorial Gradual from the Graduale Romanum, or the Responsorial Psalm or the Alleluia Pslam from the Graduale Simplex, as described in these books.