Many millions of Christians observe Christmas on January 7. In Bethlehem today, Christians gathered to welcome their bishops as celebrations began. From the Palestinian News,
Orthodox Christmas celebrations kicked off in Bethlehem as hundreds of Orthodox Christians, pilgrims and clergy paraded in the Nativity Square to receive patriarchs and bishops. The Greek Orthodox Patriarch of Jerusalem Theophilus III arrived Tuesday at Manager Square, marking the start of Christmas Eve celebrations according to the Julian calendar.... President Mahmoud Abbas as well as a representative of King of Jordan Abdullah II are expected to arrive in Bethlehem later to attend the mid night mass that would be presided over by Patriarch Theophilus III.
McGowan highlights a less well-known theory that the dates were chosen because of the tradition of linking the dates of birth and death. He writes,
Around 200 C.E. Tertullian of Carthage reported the calculation that the 14th of Nisan (the day of the crucifixion according to the Gospel of John) in the year Jesus died was equivalent to March 25 in the Roman (solar) calendar. March 25 is, of course, nine months before December 25; it was later recognized as the Feast of the Annunciation—the commemoration of Jesus’ conception. Thus, Jesus was believed to have been conceived and crucified on the same day of the year. Exactly nine months later, Jesus was born, on December 25....
In the East, too, the dates of Jesus’ conception and death were linked. But instead of working from the 14th of Nisan in the Hebrew calendar, the easterners used the 14th of the first spring month (Artemisios) in their local Greek calendar—April 6 to us. April 6 is, of course, exactly nine months before January 6—the eastern date for Christmas.It is a good article, and worth reading in full. John posted on this same topic (more thoroughly than I am here) back in December of 2011. His post is worth a look too, as he draws upon other writers, including Benedict XVI, and concludes,
None of these dates, though, need be historically reliable, but the proper calendrical date is not the point; the point is to establish theologically significant dates and dates upon which to celebrate these events. Putting too much historical or calendrical weight on any of these celebrations crashes the whole edifice to the ground.....Why is it necessary to create historical evidence where none exists? It is not necessary, unless one places too much credence in spiritual truth as equitable with historical veracity. This much I know: Jesus was born on some day and whether it was December 25th or some other day, I am happy to celebrate it.