Several of the season's best-known customs are more recent than the season itself. The Advent wreath, four candles in a ring of greenery lit one per week, is a nineteenth-century Lutheran development from Germany, popularised by the Hamburg pastor Johann Hinrich Wichern, who is credited with an early ring of candles for the children in his mission house. The Advent calendar, counting the days to Christmas behind small doors, is likewise a German innovation of around 1900.
Older and more central to the liturgy are the "O Antiphons", the seven great antiphons sung at Vespers on 17-23 December, each addressing Christ under a title drawn from the Hebrew prophets (O Wisdom, O Adonai, O Root of Jesse, and so on); their initials read backward spell a Latin acrostic, ero cras, "tomorrow I will be there". The hymn "O come, O come, Emmanuel" is a versification of them. The third Sunday, Gaudete, relaxes the penitential tone with rose vestments and a call to rejoice, a foretaste of the coming feast.