The Christmas Fast, which prepares us for the celebration of the Nativity of Christ, lasts from November 28, 2025 to January 7, 2026 (according to the new calendar).

The establishment of the Christmas Fast, as well as other multi-day fasts, dates back to the first centuries of Christianity. As early as the 4th century, Saint Ambrose of Milan, Philistius, and Blessed Augustine mentioned the Christmas Fast in their works. In the 5th century, Leo the Great wrote about the Christmas Fast. Originally, the Christmas Fast lasted seven days for some Christians, and a little longer for others. At the council of 1166, which was held during the reign of the Patriarch of Constantinople Luke and the Byzantine Emperor Manuel, all Christians were ordered to observe a 40-day fast on the eve of the great feast of the Nativity of Christ.

Patriarch Balsamon of Antioch wrote that “His Holiness the Patriarch himself said that although the days of these fasts (the Assumption and Christmas) are not determined by the rule, we should nevertheless try to follow the unwritten church tradition and we are obliged to fast … from the 15th of November”. The Christmas fast is the last multi-day fast of the year. It lasts forty days and therefore is called Lent in the church constitution, like Great Lent.

The Christmas fast was established so that we could purify ourselves before the day of Christ’s Nativity through repentance, prayer and fasting, so that with pure hearts, souls and bodies we could welcome with awe the Son of God who appeared to the world, and so that in addition to ordinary gifts and sacrifices we could offer Him our pure hearts and the desire to follow His teachings.

The founder of Christian asceticism is considered to be our Lord Jesus Christ himself, who, on the eve of embarking on the ascetic journey of redemption for the human race, strengthened himself with a long fast. And all ascetics, beginning to serve the Lord, armed themselves with fasting and did not embark on the path of the Cross in any other way than by fasting.