The Great Cycle of Life.
The life of an Orthodox Christian can be seen as being composed of five cycles. There is, first of all, the great cycle of life, which embraces the whole life of a man from birth to death, and which consists in liturgical actions which are not repeated, occurring only once in a person's lifetime. These are Holy Baptism, Holy Chrismation, and the Burial Service. In addition, there also belongs in this great cycle the Sacraments or Sacramental Blessings which bestow special grace for a particular office or vocation with the community. These are Holy Matrimony, the Monastic Tonsure and Holy Orders.
The Daily Cycle.
Another major cycle which involves the entire life of an Orthodox Christian is the daily cycle of prayers and praises offered by the Church, once every twenty-four hours. These services express our remembrance of events which happened at certain hours and contain petitions relevant to these memories.
In antiquity the day was considered to begin at sunset and thus was divided according to the following order. Night began at 6:00 p.m. (according to our reckoning) and was divided into four parts (called watches the time of changing guards): Evening (6:00 p.m. to 9:00 p.m.); Midnight (9:00 p.m. to 12:00 midnight); Cock-crow (12:00 midnight to 3:00 a.m.); and Morning (3:00 a.m. to 6:00 a.m.). Day began at 6:00 a.m. (our reckoning) and it, too, was divided into four watches (or hours). First Hour (6:00 a.m. to 9:00 a.m.); Third Hour (9:00 a.m. to 12:00 noon); Sixth Hour (12:00 noon to 3:00 p.m.); and Ninth Hour (3:00 p.m. to 6:00 p.m.).
Following this ancient pattern, Orthodox Christians begin each portion of the day with common prayer, which has resulted in the following eight Services, customarily divided into three groups: Ninth Hour, Vespers, and Compline; Nocturns (Midnight Service), Matins, and First Hour; Third and Sixth Hours. In addition to this daily pattern, in certain monasteries during certain periods of fasting, each of the Hours is followed by an intermediate Office called the Interhour. Also included in the daily cycle are the Offices for the Blessing of the Table and the Morning and Evening Prayers.
The Divine Liturgy is often included in this daily cycle, normally being served after the Sixth Hour (although, during Fast Periods it is celebrated after Vespers). Often treated as part of the daily cycle, the Divine Liturgy is not prescribed to be celebrated every day (as it is in many cathedrals and monasteries) and in a theological and mystical sense actually stands outside of chronological time since it also serves as a point of contact with the eternal, where its participants (by virtue of their partaking of the Holy Eucharist) are transported to a point outside of time where there is no past, present or future, but only the eternal Now [The Festal Menaion, trans. Mother Mary and Archimandrite Kallistos Ware, p. 40]. On days when the Divine Liturgy is not celebrated, the Service of the Typical Psalms is celebrated in its place after the Sixth Hour (it also sometimes precedes the Liturgy), thus forming part of the third group of Daily Services with the Third and Sixth Hours.
In addition to these two cycles, there are also three others: The Weekly Cycle of the Eight Tones (Octoechos), the Annual Cycle of Movable Feasts (dependent upon Pascha), and the Annual Cycle of Fixed Feasts, beginning on the first day of the Church Year September 1. These three cycles are combined and superimposed on each other, giving the Liturgical Year a constant and unfailing variety.
The Weekly Cycle.
Each day of the Weekly Cycle is dedicated to certain special memorials. Sunday is dedicated to Christ's Resurrection; Monday honors the Holy Bodiless Powers (Angels, Archangels, etc.); Tuesday is dedicated to the prophets and especially the greatest of the Prophets, St. John the Forerunner and Baptist of the Lord; Wednesday is consecrated to the Cross and recalls Judas' betrayal; Thursday honors the Holy Apostles and Hierarchs, especially St. Nicholas, Bishop of Myra in Lycia; Friday is also consecrated to the Cross and recalls the day of the Crucifixion; Saturday is dedicated to All Saints, especially the Mother of God, and to the memory of all those who have departed this life in the hope of resurrection and eternal life.
Each week of the Weekly Cycle is centered around the Eight Tones (the basis for Orthodox Church music) and each Week has its appointed Tone. On Saturday Evening of Bright Week (the Eve of St. Thomas Sunday), the cycle of Tones begins with Tone One and, week by week, the sequence continues through the successive Tones, One to Eight, changing to a new Tone every Saturday Evening, throughout the year.
The Annual Cycle of Movable Feasts.
The yearly cycle of Movable Feasts is that centered around Holy Pascha and is called movable because, being linked with the Feast of Feasts, it shifts from year to year as Pascha itself falls on a different date each year. The Feasts which comprise this cycle are Palm Sunday (the Sunday before Pascha), Holy Ascension (the fortieth day after Pascha) and Holy Pentecost (the Descent of the Holy Spirit the fiftieth day after Pascha).
The Annual Cycle of Fixed Feasts.
Each day of the year is dedicated to the memory of particular events or Saints and these memorials always fall on the same Calendar date each year. Thus, in honor of each event or Saint(s), special hymns have been composed which are added to the usual hymns and prayers of the day.
The Great Feasts.
Among the feasts of the Church Year, a place of special honor belongs to the Feast of Feasts, Holy Pascha. Next in importance come the Twelve Great Feasts, which can be divided into two groups: Feasts of the Lord and Feasts of the Mother of God.
Great Feasts of the Lord:
1. The Universal Exaltation (or Elevation) of the Life-creating Cross (Sept. 14)
2. The Nativity of Our Lord God and Savior Jesus Christ (Christmas Dec. 25)
3. The Theophany (or Epiphany) of Our Lord God and Savior Jesus Christ (Jan. 6)
4. The Entrance of Our Lord Jesus Christ into Jerusalem (Palm Sunday Sunday before Pascha)
5. The Ascension of Our Lord and Savior Jesus Christ (40 days after Pascha)
6. The Descent of the Holy Spirit (Holy Pentecost 50 days after Pascha)
7. The Transfiguration of Our Lord God and Savior Jesus Christ (Aug. 6)
Great Feasts of the Mother of God:
1. The Nativity of the Most-Holy Theotokos (Sept. 8)
2. The Entrance (or Presentation) of the Theotokos into the Temple (Nov. 21)
3. The Meeting of Our Lord Jesus Christ in the Temple (Feb. 2)
4. The Annunciation to the Most-Holy Theotokos (Mar. 25)
5. The Falling-Asleep (or Dormition) of the Most-Holy Theotokos (Aug. 15)
All of the Feasts listed above, with the exception of Palm Sunday and Holy Pentecost are preceded by a period of preparation known as the Forefeast. In addition, The Nativity of Christ and the Dormition are preceded by a special fasting period (the Nativity Fast begins on November 15 and the Dormition Fast begins on August 1). Three of the Feasts are followed, on the next day, by a distinctive commemoration known as a Synaxis: The Nativity of Christ is followed, on Dec. 26 by the Synaxis of the Most-Holy Theotokos; the Theophany is followed, on Jan. 7 by the Synaxis of St. John the Baptist; and the Annunciation is followed, on Mar. 26 by the Synaxis of the Archangel Gabriel. In addition, all except one (Palm Sunday) are followed by a festal period called the Afterfeast, during which the prior Feast is continually observed. The last day of the Afterfeast the actual close of the Feast is called the Leavetaking.