Liturgical calendar in the context of "Liturgical colours"

A Gospel Book, Evangelion, or Book of the Gospels (Greek: Εὐαγγέλιον, Evangélion) is a codex or bound volume containing one or more of the four Gospels of the Christian New Testament – normally all four – centering on the life of Jesus of Nazareth and the roots of the Christian faith. The term is also used for a liturgical book, also called the Evangeliary, from which are read the portions of the Gospels used in the Mass and other services, arranged according to the order of the liturgical calendar.

Liturgical use in churches of a distinct Gospel book remains normal, often compulsory, in Eastern Christianity, and very common in Roman Catholicism and some parts of Anglicanism and Lutheranism.

In Christian tradition, the True Cross is the original wooden cross on which Jesus of Nazareth was crucified.

It is related by numerous historical accounts and legends that Helen, the mother of Roman emperor Constantine the Great, recovered the True Cross at the Holy Sepulchre in Jerusalem, when she travelled to the Holy Land in the years 326–328. The late fourth-century historians Gelasius of Caesarea and Tyrannius Rufinus wrote that while Helen was there, she discovered the hiding place of three crosses that were believed to have been used at the crucifixion of Jesus and the two thieves, Dismas and Gestas, who were executed with him. To one cross was affixed the titulus bearing Jesus' name, but according to Rufinus, Helen was unsure of its legitimacy until a miracle revealed that it was the True Cross. This event is celebrated on the liturgical calendar as the Feast of the Exaltation of the Cross (Roodmas) by the Oriental Orthodox, Eastern Orthodox, Persian, Roman Catholic, Lutheran, and Anglican churches.

A religious festival is a time of special importance marked by adherents to that religion. Religious festivals are commonly celebrated on recurring cycles in a calendar year or lunar calendar. The science of religious rites and festivals is known as heortology.

Within the Evangelical Lutheran branch of Christianity, "festival" is part of the ranking of feast days in the liturgical kalendar.

In Christian theology, the Harrowing of Hell (Latin: Descensus Christi ad Inferos; Greek: Ἡ εἰς ᾍδου κάθοδος τοῦ Χριστοῦ – "the descent of Christ into Hell" or "Hades") is the period of time between the Crucifixion of Jesus and his resurrection. In triumphant descent, Christ brought salvation to the souls held captive there since the beginning of the world.

Christ's descent into the world of the dead is referred to in the Apostles' Creed and the Athanasian Creed (Quicumque vult), which state that he "descended into the underworld" (descendit ad inferos), although neither mention that he liberated the dead. His descent to the underworld is alluded to in the New Testament in 1 Peter 4:6, which states that the "good tidings were proclaimed to the dead". The Catechism of the Catholic Church notes Ephesians 4:9, which states that "[Christ] descended into the lower parts of the earth", as also supporting this interpretation. These passages in the New Testament have given rise to differing interpretations. The Harrowing of Hell is commemorated in the liturgical calendar on Holy Saturday.

In the liturgical calendar of the Roman Rite, a solemnity is a feast day of the highest rank celebrating a mystery of faith such as the Trinity, an event in the life of Jesus, his mother Mary, his legal father Joseph, or another important saint. The observance begins with the vigil on the evening before the actual date of the feast. Unlike feast days of the rank of feast (other than feasts of the Lord) or those of the rank of memorial, solemnities replace the celebration of Sundays outside Advent, Lent, and Easter (those in Ordinary Time).

The word comes from postclassical Latin sollemnitas, meaning a solemnity, festival, celebration of a day.

A moveable feast is an observance in a Christian liturgical calendar which occurs on different dates in different years. It is the complement of a fixed feast, an annual celebration that is held on the same calendar date every year, such as Christmas.

Whit Monday or Pentecost Monday, also known as Monday of the Holy Spirit, is the holiday celebrated the day after Pentecost, a moveable feast in the Christian liturgical calendar. It is moveable because it is determined by the date of Easter. In the Catholic Church, it is the Memorial of the Blessed Virgin Mary, Mother of the Church, marking the resumption of Ordinary Time.

Whit Monday gets its name from "Whitsunday", an English name for Pentecost, one of the three baptismal seasons. The origin of the name "Whit Sunday" is generally attributed to the white garments formerly worn by those newly baptised on this feast.

The Calendar of the Church Year is the liturgical calendar of the United States Episcopal Church. It is found in the 1979 Book of Common Prayer and in Lesser Feasts and Fasts, with additions made at recent General Conventions.

The veneration of saints in Anglicanism is a continuation of an ancient tradition from the early Church which honors important and influential people of the Christian faith. The usage of the term saint is similar to Roman Catholic and Orthodox traditions. Episcopalians believe in the communion of saints in prayer and as such the Episcopal liturgical calendar accommodates feasts for saints.