Roman Catholics and Anglicans traditionally celebrate Midnight Mass, which begins either at or sometime before midnight on Christmas Eve. This ceremony, which is held in churches throughout the world, celebrates the birth of Christ, which is believed to have occurred at night.
In recent years some churches have scheduled their "Midnight" Mass as early as 7 pm In Spanish-speaking areas, the Midnight Mass is sometimes referred to as Misa del Gallo, or "Missa do Galo", in Portuguese ("Rooster's Mass"). In the Philippines, this custom lasts for nine days, starting on December 16 and continuing daily up to December 24, during which Filipinos attend dawn Masses, usually starting at around 4:00–5:00 am In 2009 Vatican officials scheduled the Midnight Mass to start at 10 pm so the 82 year old Pope Benedict XVI would not have too late a night.
Lutherans traditionally practice Christmas Eve Eucharistic traditions typical of Germany and Scandinavia. "Krippenspiele" (Nativity plays), special festive music for organ, vocal and brass choirs and candlelight services make Christmas Eve one of the highlights in the Lutheran Church calendar. Christmas Vespers are popular in the early evening, and midnight services are also widespread in regions which are predominately Lutheran. The old Lutheran tradition of a Christmas Vigil in the early morning hours of Christmas Day(Christmette) can still be found in some regions. In eastern and middle Germany, congregations still continue the tradition of "Quempas singing": separate groups dispersed in various parts of the church sing verses of the song "He whom Shepherds once came Praising" (Quem pastores) responsively.
Methodists celebrate the evening in different ways. Some, in the early evening, come to their church to celebrate Holy Communion with their families. The mood is very solemn, and the only visible light is the Advent Wreath, and the candles upon the Lord's Table. Others celebrate the evening with services of light, which include singing the song "Silent Night" as a variety of candles (including personal candles) are lit. Other churches have late evening services at 11 pm, so the church can celebrate Christmas Day together with the ringing of bells at 12 am Others offer Christmas Day services, as well.
The annual "Nine Lessons and Carols" broadcast from King's College, Cambridge, on Christmas Eve, has established itself as one of the signs that Christmas has begun in the United Kingdom. It is broadcast outside the UK via the BBC World Service, and is also bought by broadcasters around the world.
Other churches hold a candlelight service. Some services re-enact the Nativity. Each church is able to celebrate Christmas Eve evening and Christmas Day in its own special way.
In the Eastern Orthodox Church, Christmas Eve is referred to as Paramony ("preparation"). It is the concluding day of the Nativity Fast and is celebrated as a day of strict fastingby those devout Orthodox Christians who are physically capable of doing so. In some traditions, nothing is eaten until the first star appears in the evening sky, in commemoration of the Star of Bethlehem. The liturgical celebration begins earlier in the day with the celebration of the Royal Hours, followed by the Divine Liturgy combined with the celebration of Vespers, during which a large number of readings from the Old Testament are chanted, recounting the history of salvation. After the dismissal at the end of the service, a new candle is brought out into the center of the church and lit, and all gather round and sing the Troparion and Kontakion of the Feast.
In the evening, the All-Night Vigil for the Feast of the Nativity is composed of Great Compline, Matins and the First Hour. The Orthodox services of Christmas Eve are intentionally parallel to those of Good Friday, illustrating the theological point that the purpose of the Incarnation was to make possible the Crucifixion and Resurrection. This is illustrated in Orthodox icons of the Nativity, on which the Christ Child is wrapped in swaddling clothes reminiscent of his burial wrappings. The child is also shown lying on a stone, representing the Tomb of Christ, rather than amanger. The Cave of the Nativity is also a reminder of the cave in which Jesus was buried.
In some Orthodox cultures, after the Vesperal Liturgy the family returns home to a festive meal, but one at which Orthodox fasting rules are still observed; i.e., no meat or dairy products (milk, cheese, eggs, etc.) are consumed (see below for variations according to nationality). Then they return to the church for the All-Night Vigil.
The next morning, Christmas Day, the Divine Liturgy is celebrated again, but with special features that occur only on Great Feasts of the Lord. After the dismissal of this Liturgy, the faithful customarily greet each other with the kiss of peace and the words: "Christ is Born!", to which the one being greeted responds: "Glorify Him!" (these are the opening words of the Canon of the Nativity that was chanted the night before during the Vigil). This greeting, together with many of the hymns of the feast, continue to be used until the leave-taking of the feast on December 29.
The first three days of the feast are particularly solemn. The second day is known as the Synaxis of the Theotokos, and commemorates the role of the Virgin Mary in the Nativity of Jesus. The third day is referred to simply as "the Third Day of the Nativity". The Saturday and Sunday following December 25 have special Epistle and Gospel readings assigned to them. December 29 celebrates the Holy Innocents.
Orthodox Christians observe a festal period of twelve days, during which no one in the Church fasts, even on Wednesdays and Fridays, which are normal fasting days throughout the year. During this time one feast leads into another: December 25–31 is the afterfeast of the Nativity; January 2–5 is the forefeast of the Epiphany.