Advent Sunday in the context of "Christmas and holiday season"

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 and it is followed by Christmastide, which historically in the West lasts twelve days and culminates on Twelfth Night. Christmas Day is a public holiday in many countries, is observed religiously by a majority of Christians, as well as celebrated culturally by many non-Christians, and forms an integral part of the annual holiday season.

The traditional Christmas narrative recounted in the New Testament, known as the Nativity of Jesus, 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 spread the word.

A Christmas decoration is any of several types of ornamentation used at Christmas and the greater Christmas and holiday season. Typical images on Christmas decorations include Baby Jesus, Mother Mary, angels, Father Christmas, Santa Claus, and the star of Bethlehem. Advent wreaths, nativity scenes, illuminations, and Moravian stars are popular Christmas decorations.

In many countries, such as Sweden, people start to set up their Advent and Christmas decorations on the first day of Advent. Liturgically, this is done in some parishes through a Hanging of the Greens ceremony. In the Western Christian world, the two traditional days when Christmas decorations are removed are Twelfth Night and if they are not taken down on that day, Candlemas, the latter of which ends the Christmas-Epiphany season in some denominations. Taking down Christmas decorations before Twelfth Night, as well as leaving the decorations up beyond Candlemas, is historically considered to be inauspicious.

Advent is a season observed in most Christian denominations as a time of waiting and preparation for both the celebration of Jesus's birth at Christmas and the return of Christ at the Second Coming. It begins on the fourth Sunday before Christmas, often referred to as Advent Sunday. Advent is the beginning of the liturgical year in Western Christianity. The name comes from Latin adventus ('coming; arrival'), translating the Greek parousia from the New Testament, originally referring to the Second Coming.

The season of Advent in the Christian calendar anticipates the "coming of Christ" from three different perspectives: the physical nativity in Bethlehem, the reception of Christ in the heart of the believer, and the eschatological Second Coming.

The hanging of the greens is a Western Christian ceremony in which many congregations and people adorn their churches, as well as other buildings (such as a YWCA or university), with Advent and Christmas decorations. This is done on or directly before the start of the Advent season, in preparation for Christmastide. The service involves the placement of evergreen vegetation in the parish. Items such as the evergreen wreath, in Christianity, carry the religious symbolism of everlasting life, a theological concept within that faith. As such, during the liturgy, "Biblical passages and other readings help explain the significance of the holly, the cedar, the Advent wreath, the Chrismon tree, and any other special decorations". Christmas trees are frequently erected during the hanging of the greens, although they are sometimes left bare until Christmas Eve.

Outside of a formal liturgy, in many countries, such as Sweden, people start to set up their Advent and Christmas decorations on the first day of Advent. In the Western Christian world, the two traditional days when Christmas decorations are removed are Twelfth Night, and if they are not taken down on that day, Candlemas, the latter of which ends the Christmas-Epiphany season in some denominations. Leaving the decorations up beyond Candlemas is historically considered to be inauspicious.

An Advent calendar, from the German word Adventskalender, is used to count the days of Advent in anticipation of Christmas. Since the date of the First Sunday of Advent varies, falling between November 27 and December 3 inclusive, many reusable Advent calendars made of paper or wood begin on December 1. Others start from the First Sunday of Advent.

The Advent calendar was first used by German Lutherans in the 19th and 20th centuries, and has since then spread to other denominations.