Celebration
Christmas Day is celebrated as a major festival and public holiday in countries around the world, including many whose populations are mostly non-Christian. In some non-Christian countries, periods of former colonial rule introduced the celebration (e.g. Hong Kong); in others, Christian minorities or foreign cultural influences have led populations to observe the holiday. Countries such as Japan and Korea, where Christmas is popular despite there being only a small number of Christians, have adopted many of the secular aspects of Christmas, such as gift-giving, decorations and Christmas trees. Notable countries in which Christmas is not a formal public holiday include People's Republic of China, (excepting Hong Kong and Macao), Japan, Saudi Arabia, Algeria, Thailand, Nepal, Iran, Turkey and North Korea. Christmas celebrations around the world can vary markedly in form, reflecting differing cultural and national traditions.
Among countries with a strong Christian tradition, a variety of Christmas celebrations have developed that incorporate regional and local cultures. For Christians, participating in a religious service plays an important part in the recognition of the season. Christmas, along with Easter, is the period of highest annual church attendance. In Catholic countries, the people hold religious processions or parades in the days preceding Christmas. In other countries, secular processions or parades featuring Santa Claus and other seasonal figures are often held. Family reunions and the exchange of gifts are a widespread feature of the season. Gift giving takes place on Christmas Day in most countries. Others practice gift giving on December 6, Saint Nicholas Day, and January 6, Epiphany.
For centuries, Christian writers accepted that Christmas was the actual date on which Jesus was born. In the early 18th century, scholars began proposing alternative explanations. Isaac Newton argued that the date of Christmas was selected to correspond with the winter solstice, which the Romans called bruma and celebrated on December 25. In 1743, German Protestant Paul Ernst Jablonski argued Christmas was placed on December 25 to correspond with the Roman solar holiday Dies Natalis Solis Invicti and was therefore a "paganization" that debased the true church. According to Judeo-Christian tradition, creation as described in the Genesis creation narrative occurred on the date of the spring equinox, i.e. March 25 on the Roman calendar. This date is now celebrated as Annunciation and as the anniversary of Incarnation. In 1889, Louis Duchesne suggested that the date of Christmas was calculated as nine months after Annunciation, the traditional date of the conception of Jesus.
The December 25 date may have been selected by the church in Rome in the early 4th century. At this time, a church calendar was created and other holidays were also placed on solar dates: "It is cosmic symbolism...which inspired the Church leadership in Rome to elect the winter solstice, December 25, as the birthday of Christ, and the summer solstice as that of John the Baptist, supplemented by the equinoxes as their respective dates of conception. While they were aware that pagans called this day the 'birthday' of Sol Invictus, this did not concern them and it did not play any role in their choice of date for Christmas," according to modern scholar S.E. Hijmans.
However, today, whether or not the birth date of Jesus is on December 25 is not considered to be an important issue in mainstream Christian denominations; rather, celebrating the coming of God into the world in the form of man to atone for the sins of humanity is considered to be the primary meaning of Christmas.
Some Christians have called for opposition to the commercialization of Christmas, since the exchange of purchased gifts has nothing to do with the philosophy of Christ.
Eastern Orthodox national churches, including those of Russia, Georgia, Ukraine, Macedonia, Montenegro, Serbia and the Greek Patriarchate of Jerusalem mark feasts using the older Julian Calendar. December 25 on that calendar currently corresponds to January 7 on the more widely used Gregorian calendar. However, other Orthodox Christians, such as the churches of Greece, Antioch, Alexandria, Finland and the Orthodox Church in America, among others, began using the Revised Julian Calendar in the early 20th century, which corresponds exactly to the Gregorian Calendar. These Orthodox Churches celebrate Christmas on the same day as Western Christianity. Oriental Orthodox churches also use their own calendars, which are generally similar to the Julian calendar. The Armenian Apostolic Church celebrates the nativity in combination with the Feast of the Epiphany on January 6. Armenian churches customarily use the Gregorian calendar, but some use the Julian calendar and thus celebrate Christmas Day on January 19, and Christmas Eve on January 18 (according to the Gregorian calendar).