Editing Song of Ascents (section)

===Western Christianity===
The Western [[Daily Office]] was strongly influenced by the [[Rule of Saint Benedict]], where these psalms are assigned to [[Terce]], [[Sext]] and [[Nones (liturgy)|Nones]] on weekdays. Over the centuries, however, various schedules have been used for reciting the psalms. Among the laity, the devotion of the Fifteen Psalms was adopted within [[primer (prayer book)|primer prayer books]].<ref>{{cite book|url=https://www.newadvent.org/cathen/12425a.htm|title=Catholic Encyclopedia|chapter=The Primer|author=[[Herbert Thurston|Thurston, Herbert]] |volume=12|date=1911|location=[[New York City]]|publisher=Robert Appleton Company|via=NewAdvent.org}}</ref>

In the arrangement used in the Roman Rite until 1911, Psalms 119–132 are said at [[Vespers]], from Monday to Thursday, and Psalm 133 was one of the four Psalms said every day at [[Compline]]. After the reform by [[Pope Pius X]] in 1911, and continuing in the later reform by [[Pope John XXIII]] in 1960, these psalms remained at Vespers, but not always on the same day as previously. Psalm 133 was said at [[Compline]] only on Sundays and major feasts. The 1960 reform is still in use as the Extraordinary Form of the Roman Rite.

In the modern [[Liturgy of the Hours]] of the [[Catholic Church]], the Gradual Psalms are used in several ways:
* Psalms 120–127 and 129–131 are scheduled throughout the four-week Psalter for use at Vespers; 119, 128, and 132 are scheduled for use for [[Little Hours#Reform|Daytime Prayer]], and 133 is scheduled for Night Prayer.
* Psalms 119–127 are broken into three parts, to be used as the complementary Psalmody for those who pray three daytime offices separately as Terce, Sext, and None, rather than one office of Daytime Prayer.
* They are used as the sole Psalmody at daytime prayer on [[solemnity|solemnities]], except for certain solemnities of the Lord and during the [[octave of Easter]] and those solemnities falling on Sunday.<ref>{{Citation |contribution=Plan for the Distribution of the Psalms in the Office |date=February 2, 1971 |title=General Instruction for the Liturgy of the Hours |publisher=The Catholic Liturgical Library |url=http://www.catholicliturgy.com/index.cfm/FuseAction/documentText/Index/2/SubIndex/39/ContentIndex/27/Start/2 |access-date=2008-05-18}}
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