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 feast central to the Christian liturgical year, it is preceded by the season of Advent or the Nativity Fast and initiates the season of Christmastide, which historically in the West lasts twelve days and culminates on Twelfth Night; in some traditions, Christmastide includes an octave. Christmas Day is a public holiday in many of the world's nations, is celebrated religiously by a majority of Christians, as well as culturally by many non-Christians, and forms an integral part of the holiday season centered around it.
The traditional Christmas narrative, the Nativity of Jesus, delineated in the New Testament says that Jesus was born in Bethlehem, in accordance with messianic prophecies. When Joseph and Mary arrived in the city, the inn had no room and so they were offered a stable where the Christ Child was soon born, with angels proclaiming this news to shepherds who then further disseminated the information.
Although the month and date of Jesus' birth are unknown, by the early-to-mid fourth century the Western Christian Church had placed Christmas on December 25, a date that was later adopted in the East. Today, most Christians celebrate on December 25 in the Gregorian calendar, which has been adopted almost universally in the civil calendars used in countries throughout the world. However, some Eastern Christian Churches celebrate Christmas on December 25 of the older Julian calendar, which currently corresponds to January 7 in the Gregorian calendar, the day after the Western Christian Church celebrates the Epiphany. This is not a disagreement over the date of Christmas as such, but rather a preference of which calendar should be used to determine the day that is December 25. Moreover, for Christians, the belief that God came into the world in the form of man to atone for the sins of humanity, rather than the exact birth date, is considered to be the primary purpose in celebrating Christmas.
Christmas in the United States during the post-War years (1946–1964) reflected a period of peace, productivity, and prosperity. Americans staged sumptuous Christmases and enjoyed a variety of holiday foods unknown to previous generations. Several films, foods, toys, and television programs of the era have become American Christmas traditions. Once reliant upon Germany for its ornaments, toys, and even its Christmas customs, America became self-sufficient in the post-War years with Christmas ornaments and toys being manufactured in the United States that were considerably less expensive than their German counterparts. American Christmas customs and traditions such as visits to department store Santas and letter writing to the North Pole remained intact during America's post-War years, but the era generated contributions that have endured to become traditions. NORAD's tracking of Santa's sleigh on Christmas Eve, for example, was initiated in 1955 and has become an annual tradition. The stop motion animated film, Rudolph the Red-Nosed Reindeer remains an annual telecast on American television—almost fifty years after its debut. Several Christmas firsts mark the post-War era that include the first White House Christmas card, the first Christmas postage stamp, the first opera composed for television (Amahl and the Night Visitors), and the first Elvis Presley Christmas album.