Byzantine Christian Churches observe a pre-Christmas fast called Philipovka or Philip's Fast. This is named after St Philip because it begins on Nov. 15, the day after his feast day (Nov. 14). In the Ruthenian Eparchy of Van Nuys, to which St Basil's belongs, all the faithful are to observe Wednesdays and Fridays as days of "Simple Fast", that is, no meat is to be eaten. Christmas Eve is traditionally a day of "Strict Fast", that is, no meat, eggs, milk or other animal products. (This strict fast is optional).
The pre-Christmas fast reminds us to prepare our souls and bodies for the celebration of the coming of the Son of God in the flesh, born of the Virgin Mary.
Advent - The term used by the Roman Church to describe the preparation period for Christ's Birth. It means "Coming".
Phillip - Apostle, born in Bethsaida on the shore of the Lake of Tiberias, the place of origin of Andrew and Peter. He was called in Galilee after Jesus had been baptized by the Forerunner John. (Cf. Matt 10:3, John 1:43-48, John 6:5-7, John 14:8-12) The Nativity / Theophany Fast begins at sundown at the conclusion of the day on which we celebrate his memory.
Phillip's Fast, Nativity Fast, Byzantine Advent - terms designating the 40 day preparation period before the Christmas / Theophany season. It begins at sundown on November 14th (when the Church begins a new day) and concludes at Christmas.
Traditional fasting prescriptions called for Strict Fast (no meat or dairy products) on Mondays, Wednesdays, and Fridays, and a lesser fast (abstinence from meat) on Tuesdays and Thursdays. While we are not bound to observe these fasting prescriptions, it would be appropriate to devote time to spiritual preparation amid all of our others tasks, as we anticipate the Feast of Christís Birth. Christmas Eve is a strict/black fast meaning no meat or dairy.