"Major" and "minor" hours were defined: (as do all offices in the traditional Breviary except Matins and Compline): "V. The verse is omitted if the hour begins with the Invitatory (Lauds or Office of Reading). Other components are included depending on the exact type of hour being celebrated.
Together with the Mass, it constitutes the official public prayer life of the Church.
The Liturgy of the Hours also forms the basis of prayer within Christian monasticism.
After these there is a short reading and response and the singing or recitation of the Benedictus.
Vespers has a very similar structure, differing in that Pius X assigned to it five psalms (now reduced to 2 psalms and a New Testament canticle) and the Magnificat took the place of the Benedictus.
Pope Pius X reduced this to 9 psalms or portions of psalms, still arranged in three "nocturns", each set of three psalms followed by three short readings, usually three consecutive sections from the same text.
Pope Paul VI's reform reduced the number of psalms or portions of psalms to three, and the readings to two, but lengthened these.By the end of the 5th century, the Liturgy of the Hours was composed of seven offices.Of these seven, Compline seems to have been the last to appear, because the 4th-century Apostolic Constitutions VIII iv 34 do not mention it in the exhortation "Offer up your prayers in the morning, at the third hour, the sixth, the ninth, the evening, and at cock-crowing".In the Psalms are found expressions like "in the morning I offer you my prayer"; "At midnight I will rise and thank you" ; "Evening, morning and at noon I will cry and lament"; "Seven times a day I praise you".The Apostles observed the Jewish custom of praying at the third, sixth and ninth hour and at midnight (Acts 10:3, 9; ; etc.).Within Lutheranism, it is contained within the liturgical books used by the various Lutheran church bodies, such as the Lutheran Church Missouri Synod, and the Evangelical Lutheran Church in America.