The word liturgy means common work or action. The Divine Liturgy is the common work of the Orthodox Church. In this gathering, we come together to hear the Word of God spoken through the reading of Scripture; and then we partake of the Word of God through the preparation and consecration of the Body and Blood of Christ (The Sacrament of the Eucharist or Holy Communion).
The Divine Liturgy is always celebrated by Orthodox Christians on Sunday. This is the Lord's Day which is symbolic of the first day of creation and the eight day - which is symbolic of Christ's resurrection from the dead. The Divine Liturgy is also celebrated by the Church on special feast days.
In the Orthodox Church the liturgical day begins in the evening with the setting of the sun. This practice follows the Biblical account of creation: “And there was evening and there was morning, one day” (Gen 1:5). The Vespers service is the primary evening service in parish settings. On Saturday evening, Great Vespers is served which transitions us to Sunday - the day of resurrection.
The Kathisma Reading is a service in which we read sections of the Psalter (Book of Psalms). This practice comes from the monastic practice of chanting the Psalms in a quiet and meditative form so that the listener can not only hear the words with his ears, but also with his heart. We chant this service on Tuesday and Thursday evenings when there are no other perscribed services.