Editing Trinity Sunday (section)

===Roman Catholicism===
In the [[Roman Catholic Church]], it is officially known as the ''Solemnity of the Most Holy Trinity''. Prior to the reforms of the [[Second Vatican Council]], it marked the end of a three-week period during which church weddings were forbidden. The period began on [[Rogation Sunday]], the fifth Sunday after [[Easter]].{{cn|date=May 2021}} The prescribed [[liturgical colours|liturgical color]] is white.<ref name=":0">{{Cite web |title=Liturgical Calendar |url=http://www.usccb.org/about/divine-worship/liturgical-calendar/index.cfm |access-date=2019-11-30 |website=www.usccb.org}}</ref>

In the traditional [[Liturgy of the Hours|Divine Office]], the [[Athanasian Creed]] (''Quicumque vult'') is said on this day at [[Prime (liturgy)|Prime]]. Before 1960, it was said on all Sundays after [[Epiphany (Christian)|Epiphany]] and Pentecost which do not fall within [[Octave (liturgical)|Octaves]] or on which a feast of Double rank or higher was celebrated or commemorated, as well as on Trinity Sunday. The 1960 reforms reduced it to once a year, on this Sunday.

In the 1962 Missal, the Mass for the First Sunday After Pentecost is not said or commemorated on Sunday (it is permanently impeded there by Trinity Sunday), but is used during the week if the ferial Mass is being said.<ref name=":0" />

The Thursday after Trinity Sunday is observed as the Feast of [[Corpus Christi (feast)|Corpus Christi]]. In some countries, including the [[United States]],<ref name=":0" /> [[Canada]], and [[Spain]], it may be celebrated on the following Sunday, when the faithful are more likely to attend Mass and be able to celebrate the feast.