It was between 398 and 402 AD that Constantinople, the Mother Church for eastern and central European Christians, began to celebrate Christmas as a distinct feast day on December 25th.
This was introduced to the Apostolic See of Constantinople by its illustrious titular of that time, St John Chrysostom (from 407 AD). The Eastern Apostolic See of Alexandria celebrated Christmas and the Epiphany on January 6th as early as the fourth century.
At Antioch, Christmas was introduced around 386 AD by the same St John Chrysostom. The See of Jerusalem did not introduce Christmas until as late as the sixth century.
Before its official introduction as a distinct feast, the Eastern patriarchates celebrated Christmas in association with the Great Festival of Lights (Epiphany or Theophany) on January 6th. In fact to this day it is the Epiphany, celebrating the Baptism of Christ and centred on the public manifestation of God as Trinity at the River Jordan, which is incomparably greater to them than Christmas.
As at Rome, where Christmas was celebrated as early as 354 AD, the East has gradually acknowledged Christmas as a distinct celebration to be observed on December 25th.
That day does not represent the actual historical date of the birth of Christ, which remains unknown. It is a conventional date which most probably originated at Rome where Christians wished to "Christianise" the pagan festival of Natalis Invicti.
That was the feast of the "invisible" sun (winter solstice), observed by the Romans on December 25th and preceded by the public calendae or the public pre-announcements of the coming festival.
To this day in the East, Christmas is pre-announced by the singing of carols, while its liturgical festal hymn to Christ is The Sun of Righteousness.
In the East, since 1923, when a pan-orthodox council at Constantinople endorsed the use of the revised Julian calendar (known in the West as the Gregorian calendar) by local national Churches, those countries which adopted the change - Greece, Cyprus, Romania and Bulgaria - celebrate Christmas on December 25th.
Those Churches which have not yet accepted the "new" calendar, such as Russia and Serbia, celebrate Christmas on January 7th, which is December 25th according to the unrevised Julian calendar.
From a religious point of view, what is important is not so much the date as is the actual manner of celebrating Christmas. It would be appropriate, therefore, to consider briefly some points of similarity as well as some obvious differences between Eastern and Western celebration of Christmas.
As in the West, in the East Christmas has a powerful family and social appeal. Like no other feast, Christmas unites the members of Christian families, levels the gap between generations, heals enmities and inspires all to be "human" again.
Unlike the West, where Christmas ranks supreme, in the East it is Easter, centred on the Cross and the Resurrection of Christ, which is the supreme festival of the year.
Also in the East, Christmas lacks the commercial side to the feast so typical of the West.
In the East it is preceded by a Lenten fast of 40 days, from November 15th. This is a time for reflection, self-restraint and inner healing in the sacrament of confession.
It is an overall "making-ready" by experiencing a real sense of expectation and anticipation of the great mystery of the Incarnation. In countries such as Romania for instance during the last days of Advent, especially on Christmas Eve, groups of the faithful go "caroling", carrying the sacred icon of the Nativity.
The Orthodox icon of Christmas is in itself a revelation. It renders not only the cosmic significance of the Incarnation but safeguards the necessary balance between the divinity and humanity of Christ, emphasising neither at the expense of the other.
On Christmas Day, everyone takes part in the divine liturgy, and on returning home the celebrations begin. The Eastern festive season begins on Christmas Day and ends on January 7th, the day after the Epiphany when all who are called John celebrate their name day.
These two weeks of celebration, marking also the end of one year and the beginning of another, is a time of inner renewal and of regeneration, brought about by our participation in the mysteries of the faith we celebrate.
Thus, in a short space of time we move spiritually from Bethlehem to the Jordan, where we witness the manifestation of the deity as our tri-une God. Indeed, on January 6th, at the Baptism of Christ, the nature of the water is itself consecrated and returned to its primordial pristine condition, becoming for us a means of salvation.
In our world of fantastic technological progress and material plenty, but also of deep spiritual poverty and disorientation, Christmas reveals to us values which are altogether different in that they are of an everlasting nature. These values are related to the very core of our Christmas celebration, for unto us a Son is given and his name is Emmanuel which means God is with us.
Father Ireneu Ioan Craciun is parish priest at the Greek Orthodox Church of the Annunciation in Arbour Hill, Dublin