Why and when the Christian Church selected DEC-25 for Jesus' birthday
The actual birthday of Jesus was forgotten by the early Christian movement. Various groups at the time celebrated his birth on JAN-6, APR-21, MAY-1 etc. By the 4th century, the church selected the approximate time of the winter solstice as the date to recognize Jesus' birth. They picked up this date from Pagan sources. As luck would have it, the autumn equinox about SEP-21 might have been a more accurate choice.
About the reason for the season:
the winter solstice: The winter solstice occurs about DEC-21 each year. It is the day of the year when the night is longest and the daytime shortest. Many centuries ago, during the early history of the Christian religion, it was a time of high anxiety throughout the Northern Hemisphere. For the previous six months, the daylight hours had been progressively shortening and the noonday Sun had been lower in the sky each day. There was a fear that the Sun would continue this trend, that the cold season might continue forever, and warmth might never return to Earth.
Using the crude instruments available, ancient astronomers were able to detect by DEC-25 of each year that the daytime had become noticeably longer and the noonday Sun was once more higher in the sky. This date was chosen, and remains, the traditional date for followers of many different Pagan an Neopagan religions to celebrate the rebirth of the Sun. Following the solstice, each succeeding day has slightly more sunlight than the previous day. It was interpreted as a promise that warmth would return once more to the Earth. Numerous pre-Christian Pagan religions honored a birth or rebirth of one of their gods or goddesses on or about that day. Their deities were typically called: Son of Man, Light of the World, Sun of Righteousness, Bridegroom, and Savior.
Some examples of gods whos birthdays were honored on that day are:
Roman Pagan Religion: Attis was a son of the virgin Nana. His birth was celebrated on DEC-25. He was sacrificed as an adult in order to bring salvation to mankind. He died about MAR-25, after being crucified on a tree, and descended for three days into the underworld. On Sunday, he arose, as the solar deity for the new season. His followers tied an image of Attis to a tree on "Black Friday," and carried him in a procession to the temple. ["Black Friday" has a very different meaning today.] His body was symbolically eaten by his followers in the form of bread. Worship of Attis began in Rome circa 200 BCE. 1
Saturnalia was a Roman seven-day celebration starting each DEC-17. It was "... marked by unrestrained revelry and often licentiousness; an orgy." 2
During his reign of 270 to 275 CE, the Roman Emperor Aurelian attempted to increase unity within the Roman Empire by establishing Sol Invictis (the Unconqured Sun) as the supreme god of the Empire. He proclaimed DEC-25 as Natalis Solis Invicti (The Birth of the Unconquered Sun) circa 274 CE. 3 This celebration continues today among Neopagan followers of the reconstructed Roman neopagan religion, Nova Roma.
羅馬皇帝奧勒良在公元270-275年的統治期間曾試圖將索爾（無敵太陽神）提升成羅馬帝國的至高之神，好加強帝國的團結。他在公元247年宣布12月25日就是Natalis Solis Invicti（無敵太陽神的誕辰）。（註3）崇尚羅馬異教的新異教主義團體，新羅馬直到今天都還會繼續這個日子。
Greek Pagan Religion: Dionysus is another savior-god whose birth was observed on DEC-25. He was worshipped throughout much of the Middle East as well as in Greece. He had a center of worship in Jerusalem in the 1st century BCE. Some ancient coins were found in Gaza with Dionysus on one side and JHWH (Jehovah) on the other. In later years, his flesh and blood were symbolically eaten in the form of bread and wine. He was viewed as the son of Zeus, the Father God. This religion has been reconstructed in recent decades by Hellenic Neopagans.
Egyptian Pagan Religion: Osiris is a savior-god who had been worshipped as far back as Neolithic times. "He was called Lord of Lords, King of Kings, God of Gods...the Resurrection and the Life, the Good shepherd...the god who 'made men and women be born again'" 4 Three wise men announced his birth. His followers ate cakes of wheat which symbolized his body. Many sayings associated with Osiris were copied into the Bible with minimal alteration. These include:
23rd Psalm: an appeal to Osiris as the good Shepherd to lead believers through the valley of the shadow of death and to green pastures and still waters.
Lord's Prayer: "O amen, who art in heaven..."
Many parables that are attributed to Jesus.
Worship of Osiris, and celebration of his DEC-25 birth, spread to many places in the Roman Empire by the end of the 1st century BCE. This worship continues today among followers of Kemetism -- a Neopagan revival of ancient Egyptian religions.
Persian Pagan Religion: Mithra was a Persian god-man and savior. Worship of Mithra became common throughout the Roman Empire, particularly among their civil service and military. Mithraism was a competitor of Christianity until the late 4th century CE when Christianity became the state religion, Mithraism was suppressed, and its priests exiled or executed. Mithra was believed to have been born on DEC-25, circa 500 BCE. His birth was witnessed by shepherds and by Magi who carried gifts. His birthday was celebrated as the "Dies Natalis Solic Invite," The "Birthday of the Unconquered Sun." Some followers believed that he was born of a virgin. During his life, he performed many miracles, cured many illnesses, and cast out devils. He celebrated a Last Supper with his 12 disciples. He was believed to have ascended to Heaven at the time of the spring equinox, about March 21. 1 His birth as the "Sun of Righteousness" was celebrated on DEC-25.
波斯異教：密特拉是波斯的神者與救世主。密特拉崇拜遍佈整個羅馬帝國，在公務員和軍隊中尤為常見。直到基督教在公元4世紀末被獨尊之前，密特拉教一直是基督徒最大的競爭對手，但後來密特拉教的祭司都遭到了流放或處決。據說密特拉出生在大約公元前500年的12月25日。牧羊人和帶著禮物的賢士見證了他的出生。他的生日被稱為“Dies Natalis Solic Invite”，亦即“無敵太陽神的生日”。有些追隨者相信他是處女之子。他在一生中行過很多奇蹟，包括治病和趕鬼。他與他的12名門徒進行了最後的晚餐。相傳他是在春分之時，差不多3月21日的時候升上天堂。（註1）他的生日被以“公義的太陽神”之名在12月25日慶祝。
It is farily obvious that many attributes, including the birth dates, of gods were shared among various Pagan religions in ancient time, and that during the first and second century, a lot of these were picked up by Christianity.
December 25 transitioned from a Pagan celebration to Jesus' birthday:
The actual date of Jesus' birthday had long been forgotten by the time that some of the early Church leaders advocated that his birth be celebrated:
Clement of Alexandria (c.150-c.215) noted that others had suggested APR-18, APR-19 and MAY-28. He preferred MAY-20.
Hippolytus (c.170-c.236) suggested JAN-02.
About 220 CE, Turtullian declared that Jesus died on MAR-25 of the year 29 CE. This led to the widespread belief that Jesus was born on or about the same date about three decades earlier. This came from the Jewish belief at the time that prophets died at an "integral age" -- either an anniversary of their birth or of the approximate date of their conception. 4
In 221 CE, Sextus Julius Africanus' book Chronographiai suggested that DEC-25 was Jesus' birthday. He based the estimate on the nominal length of human pregnancy of nine months, using the already established Festival of the Annunciation as a starting point.
Others preferred NOV-17, NOV-20, or MAR-25. Even the nominal date of the Spring Equinox, MAR-21, was suggested because that was believed to be the date when God created the Sun. Jesus was often identified with the Sun by the early Christian church.
However, Origen (c.185-c.254) taught that the religious celebration of birthdays belonged to the worship of Pagan gods, and should be rejected by Christians. He believed that only sinners, not saints, celebrated their birthdays. 4
Elesha Coffman, the Christian History editor for Christianity Today, suggests that the decision of DEC-25 for Jesus' birthday was made as early as 273 CE. This was four decades before Emperor Constantine recognized Christianity as a legal religion by Edict of Milan during 313-FEB. At the time, various religions in the Roman Empire had celebrations at this time as noted above, while other religions observed the Winter Solstice itself.
Saturnalia (the Festival of Saturn) was celebrated from DEC-17 to 23 throughout the Roman Empire. In late 274, the Roman Emperor Aurelian blended Saturnalia with a number of birth celebrations of savior Gods from other religions, into a single holy day: DEC-25. 5
The people of the Roman Empire were accustomed to celebrating the birth of a God on that day. So, it was relatively easy for the church to later alter its meaning to a celebration of Jesus' birth.
The first known celebration of Christmas was in Rome during 336 CE. 6 Well established celebrations of Christmas occurred there by the year 360 CE. It spread to Constantinople in 379, to Antioch about 380, and to Alexandria about 430 CE. 4
The following information sources were used to prepare and update the above essay. The hyperlinks are not necessarily still active today.
1. B.G. Walker, "The Woman's Encyclopedia of Myths and Secrets," Harper & Row, (1983) Review/order the book "Saturnalia," The American Heritage Dictionary of the English Language, (1992), Page 1605. Excerpted at: http://www.the-goldenrule.name/
2. Christian Korner, "Aurelian and rebellions during his reign (A.D. 270-275), at: http://www.roman-emperors.org/
3. "Christmas - History," Wikipedia, as on 2008-JUN-14, at: http://en.wikipedia.org/
4. Elesha Coffman, "Why Why December 25? For the church's first three centuries, Christmas wasn't in December—or on the calendar at all," Christianity Today, 2008-AUG-08, at: http://www.christianitytoday.com/
5. "Christmas," The Oxford Companion to Christian Art and Architecture, (1996), Page 104. Excerpted at: http://www.the-goldenrule.name/