The custom of extending the most important feasts to a period of eight days was inherited by the Church from the Old Testament, which prescribes that this be done for Passover, the feast of Tabernacles, and the dedication of the temple. In the Roman Rite, this extension is simply called an octave, and when it is done, always lasts for seven days after the main feast. This is the original and oldest standard, universally attested for the celebration of Easter.
A Greek icon of the Great Deesis (i.e. “supplication”, the Virgin and the Baptist to either side of Christ), with most of the Twelve Great Feasts painted on the doors, ca. 1540-49. (Image from Wikimedia Commons by Daderot, CC0 1.0. Universal.)
In the Byzantine Rite, on the other hand, the length of such an extension varies from feast to feast, and the period is called the After-feast, while the final day is called the Leave-taking. Easter is ranked by itself above all other celebrations, and its Leave-taking is on the day before the Ascension; including Holy Saturday, this makes a total of forty days. Just beneath it in rank is a group called the Twelve Great Feasts, eight of Our Lord and four of Our Lady. Most of these have a Fore-feast, the equivalent of a vigil in the Roman Rite, but that of Christmas lasts for five days, and that of Epiphany for four. I list them here with their length of the respective After-feasts, including the day of the Leave-taking.
Sept. 8 – the Birth of the Mother of God (4 days)
Sept. 14 – the Exaltation of the Cross (7 days)
Nov. 21 – the Presentation of the Mother of God in the Temple (4 days)
Dec. 25 – the Nativity of the Lord (6 days)
Jan. 6 – the Theophany (8 days)
Feb. 2 – the Presentation of the Lord (7 days)
Mar. 25 – the Annunciation (no Afterfeast)
Palm Sunday (no Afterfeast)
The Ascension (8 days)
Pentecost (6 days)
Aug. 6 – The Transfiguration (7 days)
Aug. 15 – the Dormition of the Mother of God (8 days)
To these we must add the very ancient feast of Mid-Pentecost, which is not counted among the twelve, but which nevertheless has an After-feast of seven days. Therefore, only three among the twelve, the Exaltation of the Cross, the Presentation of the Lord, and the Transfiguration, plus Mid-Pentecost, conform to the Old Testament manner of celebrating an octave.
Most of these variations can be explained very easily. The After-feast of the Nativity of the Virgin is interrupted by another very ancient feast, the Dedication of the church of the Holy Sepulcher in Jerusalem, which is also the Fore-feast of the Exaltation; that of the Presentation of the Virgin imitates it. The eighth day of Christmas is itself a feast, that of the Circumcision, which is also the day of St Basil the Great; the eighth day of Pentecost is the Byzantine feast of All Saints. The Annunciation has no After-feast since it always occurs in Lent or within the Easter octave; for Palm Sunday, an After-feast would extend into Holy Week.
An icon of the Dormition of the Virgin painted by El Greco (Domenikos Theotokopoulos; 1541-1614), ca. 1565, venerated in a church titled to this feast on the Greek island of Syros, about 75 miles to the southeast of Athens. In 1983, the artist’s signature was discovered on the base of the candelabrum; it is believed to be one of the last works he executed while still living in his native place, the island of Crete, before moving to Venice in 1567.
The After-feast of the Dormition presents a particularly interesting case. August 15th was a feast of the Virgin before September 8th or November 21st were, although the first attestation of it as such does not explicitly call it the Dormition or Assumption. The length of its After-feast, 8 days, is that of the other two put together (four and four), indicating its place as the greatest of the Marian feasts. One may also note that it has the same length in toto as the Ascension, nine days, which reminds us not only of the essential similarity between the two feasts, but also of the nine choirs of Angels, since both feasts speak repeatedly of the Angels, and their wonder at seeing our human nature raised up to heaven.
“The Lord was taken up into the heavens, that He might send the Paraclete to the world; the heavens prepare His throne, the clouds His rising; the Angels wonder, seeing a man above them…” (the first hymn of Vespers of the Ascension).
“The Angels are astonished, seeing the Dormition of the Virgin, how She departs from earth on high.” (The refrain of the first Ode of the first Canon of the Dormition.)
The Byzantine Rite also has a formally designated beginning to its liturgical year on September 1st, known as the feast of the Indiction, a name which originated with an ancient Roman cycle of taxation. The first of the Twelve Great Feasts to occur after the Indiction, and the first to occur in history, is the Nativity of the Virgin Mary on September 8th; the last to occur before it, and the last to occur in history, is the Assumption. It seems very unlikely that this arrangement is merely coincidental.
The Indiction is also considered the day on which God began to create the world, a tradition to which its liturgical texts repeatedly refer. For example, the tropar at the Divine Liturgy reads as follows.
“Maker of all creation, Who settest times and seasons in Thy power, bless the crown of the year of Thy goodness, o Lord, keeping in peace Thy kings and Thy city, by the prayers of the Mother of God, and save us.”
Since the Indiction represents the beginning of creation, note that between it and the Birth of the Virgin there are seven day inclusive: the six days of creation, and the seventh on which God rested, as recounted at the beginning of Genesis. This is the creation which falls in Adam, and awaits redemption in the New Adam, a redemption which begins with the coming of His Mother into the world, the feast that is celebrated on September 8th.
After the Leave-taking of the Dormition on August 23rd, the remainder of the year is eight days, August 24-31. These days represent the creation after Christ restored it by rising on the day after the seventh, which is both the first day, the beginning a new creation, and the eighth. The Virgin Mary, the first person to be taken into the glory of heaven body and soul, is the first-fruits of the redemption of our fallen humanity, the redemption which will be perfected at the end of time in the rest of us.