body of traditions and lore. Because gift-giving and many other aspects of the Christmas festival involve heightened economic activity, Christmas has become Christmas is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people around the world. A liturgical feast central to Christianity, Christmas preparation begins on the First Sunday of Advent. Advent is followed by Christmastide, which historically in the West lasts twelve days and culminates on Tw 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 areas, 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, where Christmas is popular despite there being only a small number of Christians, have adopted many of the cultural aspects of Christmas, such as gift-giving, decorations, and Christmas trees. A similar example is in Turkey, being Muslim-majority and with a small number of Christians, where Christmas trees and decorations tend to line public streets during the festival. Many popular customs associated with Christmas developed independently of the commemoration of Jesus's birth, with some claiming that certain elements are Christianized and have origins in pre-Christian festivals that were celebrated by pagan populations who were later converted to Christianity; other scholars reject these claims and affirm that Christmas customs largely developed in a Christian context. 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-centu 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 areas, 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, where Christmas is popular despite there being only a small number of Christians, have adopted many of the cultural aspects of Christmas, such as gift-giving, decorations, and Christmas trees. A similar example is in Turkey, being Muslim-majority and with a small number of Christians, where Christmas trees and decorations tend to line public streets during the festival. Many popular customs associated with Christmas developed independently of the commemoration of Jesus's birth, with some claiming that certain elements are Christianized and have origins in pre-Christian festivals that were celebrated by pagan populations who were later converted to Christianity; other scholars reject these claims and affirm that Christmas customs largely developed in a Christian context. 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 transformation. The celebration of Christmas was banned on more than one occasion within certain groups, such as the Puritans and Jehovah's Witnesses (who do not celebrate birthdays in general), due to concerns that it was too unbiblical. Celtic winter herbs such as mistletoe and ivy, and the custom of kissing under a mistletoe, are common in modern Christmas celebrations in the English-speaking countries. The pre-Christian Germanic peoples—including the Anglo-Saxons and the Norse—celebrated a winter festival called Yule, held in the late December to early January period, yielding modern English yule, today used as a synonym for Christmas. In Germanic language-speaking areas, numerous elements of modern Christmas folk custom and iconography may have originated from Yule, including the Yule log, Yule boar, and the Yule goat. Often leading a ghostly procession through the sky (the Wild Hunt), the long-bearded god Odin is referred to as "the Yule one" and "Yule father" in Old Norse texts, while other gods are referred to as "Yule beings". On the other hand, as there are no reliable existing references to a Christmas log prior to the 16th century, the burning of the Christmas block may have been an early modern invention by Christians unrelated to the pagan practice. Among countries with a strong Christian tradition, a variety of Christmas celebrations have developed that incorporate regional and local cultures. For example, in eastern Europe Christmas celebrations incorporated pre-Christian traditions such as the Koleda, which shares parallels with the Christmas carol. The exchanging of gifts is one of the core aspects of the modern Christmas celebration, making it the most profitable time of year for retailers and businesses throughout the world. On Christmas, people exchange gifts based on the Christian tradition associated with Saint Nicholas, and the gifts of gold, frankincense, and myrrh which were given to the baby Jesus by the Magi. The practice of gift giving in the Roman celebration of Saturnalia may have influenced Christian customs, but on the other hand the Christian "core dogma of the Incarnation, however, solidly established the giving and receiving of gifts as the structural principle of that recurrent yet unique event", because it was the Biblical Magi, "together with all their fellow men, who received the gift of God through man's renewed participation in the divine life". However, Thomas J. Talley holds that the Roman Emperor Aurelian placed the alternate festival on December 25 in order to