"Ceiling Mosaic -Christus helios, the mosaic of Sol in Mausoleum M, which is interpreted as Christ-Sol (Christ as the Sun). Detail of vault mosaic in the Mausoleum of the Julii. From the necropolis under St. Peter's Mid-3rd century Grotte Vaticane, Rome. Mosaic of the Vatican grottoes under St. Peter's Basilica, on the ceiling of the tomb of the Julii.v Representation of Christ as the sun-god Helios or Sol Invictus riding in his chariot. Dated to the 3rd century AD. "Early Christian and pagan beliefs are combined in this third century mosaic of Christ as a sun-god. The triumphant Christ/god, with rays shooting from his head, is pulled aloft by two rearing horses in his chariot. The Dionysian vines in the background become the vines of Christ." Title: Christ as Sol Invictus Late 3rd century
"The First Apology" by St. Justin Martyr, an early Christian, quotes Psalm 19:5-6, a verse that was very popular with early Christians. It was associated with the ancient Christian custom of praying toward the East, the direction of Christ's Ascension and second coming, instead of toward Jerusalem as Jews did: "And hear how it was foretold concerning those who published His doctrine and proclaimed His appearance, the above-mentioned prophet and king [David] speaking thus by the Spirit of prophecy. "....In the sun has He set His tabernacle, and he as a bridegroom going out of his chamber shall rejoice as a giant to run his course." Christ was also associated with "the Sun of justice with its healing rays", a Messianic image from Malachi 3:20." Christ as Sol
"Sol Invictus ("Unconquered Sun") was the official sun god of the later Roman Empire and a patron of soldiers. In 274 the Roman emperor Aurelian made it an official cult alongside the traditional Roman cults. Scholars disagree whether the new deity was a refoundation of the ancient Latin cult of Sol, a revival of the cult of Elagabalus or completely new. The god was favored by emperors after Aurelian and appeared on their coins until Constantine. The last inscription referring to Sol Invictus dates to 387 AD and there were enough devotees in the 5th century that Augustine found it necessary to preach against them.
"The idea, particularly popular in the 18th and 19th centuries, that the date of 25 December for Christmas was selected in order to correspond with the Roman festival of Dies Natalis Solis Invicti, or "Birthday of the Unconquered Sun", is challenged today." Sol Invictus
"Since 1970, the rule for the Roman Rite of the Catholic Church is: "The Epiphany of the Lord is celebrated on 6 January, unless, where it is not observed as a Holy day of obligation, it has been assigned to the Sunday occurring between 2 and 8 January."
"In the Church of England also, the feast may be celebrated on the Sunday between January 2 and 8 inclusive  although the official date of epiphany in the UK is always January 6. (...) In the Episcopal Church in the United States, the feast of the Baptism of the Lord is always the Sunday after January 6.
"Alternative names for the feast include (τα) Θεοφάνια, Theophany as neuter plural rather than feminine singular, η Ημέρα των Φώτων, i Imera ton Foton (modern Greek pronunciation), hē hēmera tōn phōtōn (restored classic pronunciation), "The Day of the Lights", and τα Φώτα, ta Fota, "The Lights".
"The earliest reference to Epiphany as a Christian feast was in A.D. 361, by Ammianus Marcellinus. St. Epiphanius says that January 6 is hemera genethlion toutestin epiphanion (Christ's "Birthday; that is, His Epiphany"). He also asserts that the Miracle at Cana occurred on the same calendar day." Epiphany on Wikipedia
"Although probably the best-known Roman holiday, Saturnalia as a whole is not described from beginning to end in any single ancient source. Modern understanding of the festival is pieced together from several accounts dealing with various aspects. The Saturnalia was the dramatic setting of the multivolume work of that name by Macrobius, a Latin writer from late antiquity who is the major source for information about the holiday. In one of the interpretations in Macrobius's work, Saturnalia is a festival of light leading to the winter solstice, with the abundant presence of candles symbolizing the quest for knowledge and truth. The renewal of light and the coming of the new year was celebrated in the later Roman Empire at the Dies Natalis of Sol Invictus, the "Birthday of the Unconquerable Sun," on December 25." Saturnalia on Wikipedia
"The original date of the celebration in Eastern Christianity was January 6, in connection with Epiphany, and that is still the date of the celebration for the Armenian Apostolic Church and in Armenia, where it is a public holiday. As of 2013, there is a difference of 13 days between the modern Gregorian calendar and the older Julian calendar. Those who continue to use the Julian calendar or its equivalents thus celebrate December 25 and January 6, which on the Gregorian calendar translate as January 7 and January 19. For this reason, Egypt, Ethiopia, Eriteria, Russia, Georgia, Ukraine, Serbia, the Republic of Macedonia, and the Republic of Moldova celebrate Christmas on what in the Gregorian calendar is January 7. Eastern Orthodox Churches in Bulgaria, Greece, Romania, Antioch, Alexandria, Albania, Finland, and the Orthodox Church in America celebrate Christmas on December 25 in the revised Julian calendar, corresponding to December 25 also in the Gregorian calendar.
"Many popular customs associated with Christmas developed independently of the commemoration of Jesus' birth, with certain elements having origins in pre-Christian festivals that were celebrated around the winter solstice by pagan populations who were later converted to Christianity. These elements, including the Yule log from Yule and gift giving from Saturnalia, became syncretized into Christmas over the centuries. The prevailing atmosphere of Christmas has also continually evolved since the holiday's inception, ranging from a sometimes raucous, drunken, carnival-like state in the Middle Ages, to a tamer family-oriented and children-centered theme introduced in a 19th-century reformation. Additionally, the celebration of Christmas was banned on more than one occasion within certain Protestant groups, such as the Puritans, due to concerns that it was too pagan or unbiblical." Christmas
"Yule or Yuletide ("Yule time") is a religious festival observed by the historical Germanic peoples, later being absorbed into and equated with the Christian festival of Christmas. The earliest references to Yule are by way of indigenous Germanic month names (Ærra Jéola (Before Yule) or Jiuli and Æftera Jéola (After Yule). Scholars have connected the celebration to the Wild Hunt, the god Odin and the pagan Anglo-Saxon Modranicht." Yule on Wikipedia
"The Christkind (German "Christ-child", pronounced [kstknt]) is the traditional Christmas gift-bringer in regions of Austria, the Czech Republic, Croatia, parts of Germany, Italy, Liechtenstein, Luxembourg, Portugal, Switzerland, Slovakia, Hungary, France, Upper-Silesia in Poland, parts of Hispanic America, in certain areas of southern Brazil and in the Acadiana region of Louisiana. In Italian, it is called Gesù Bambino, in Portuguese Menino Jesus ("Jesus Boy"), in Hungarian Jézuska ("Little Jesus"), in Slovak Ježiško ("Little Jesus"), in Czech Ježíšek ("Little Jesus"), in Latin America "Nino Dios" ("God Child") and in Croatian Isusić ("Little Jesus").
"Promulgated by Martin Luther, explicitly to discourage the figure of St. Nicholas, at the Protestant Reformation in 16th-17th-century Europe, many Protestants changed the gift bringer to the Christ Child or Christkindl, and the date of giving gifts changed from December 6 to Christmas Eve. A gift-bringer familiar to children in Central Europe, the Christkind bears little resemblance to the infant of Bethlehem.  The Christkind was adopted in Catholic areas during the 19th century, while it began to be gradually replaced by a more or less secularized version of Saint Nicholas, the Weihnachtsmann (Father Christmas, Santa Claus) in Protestant regions.
"The Christkind is a sprite-like child, usually depicted with blond hair and angelic wings. Martin Luther intended it to be a reference to the incarnation of Jesus as an infant. Sometimes the Christ Child is, instead of the infant Jesus, interpreted as a specific angel bringing the presents, as it appears in some processions together with an image of little Jesus Christ. It seems also to be rooted in the Alsatian-born myth of a child bringing gifts to the baby Jesus.  Children never see the Christkind in person, and parents tell them that Christkind will not come and bring presents if they are curious and try to spot it. The family enters the living room, where the Christmas tree has been put up, for the opening of presents (the Bescherung) when the parents say that they think that the Christkind who has brought the presents has now left again. In some traditions, the departure is announced by the ringing of a small bell, which the parents pretend to have heard or which is secretly done by one of the adults in the family.
"Since the 1990s, the Christkind is facing increasing competition from the Weihnachtsmann in the American version of Santa Claus, caused by the use of Santa Claus as an advertising figure." Christkind - Wikipedia