 The equivalent of Advent in Eastern Christianity is called the Nativity Fast, but it differs in length and observances, and does not begin the liturgical church year as it does in the West.The Eastern Nativity Fast does not use the equivalent "parousia" in its preparatory services.It is not known when the period of preparation for Christmas that is now called Advent first began – it was certainly in existence from about 480 – and the novelty introduced by the Council of Tours of 567 was to order monks to fast every day in the month of December until Christmas.