The compline is the second service of the liturgical day, and is normally read before going to sleep. The Compline is normally read at home, not in church. The exception is during Great Lent, when parishes ideally hold Compline every evening Monday – Friday.
Since it is connected with sleep, the main theme of Compline is to reflect on the day that has gone by, asking forgiveness for our failings, support in our weaknesses, God’s help should we be given another day and, if not, God’s mercy on the day of judgment.
After the customary introductory prayers, we read three Psalms — 50 (51), 69 (70), 142 (143) — a doxology, and the Nicene Creed. After the Creed, it is customary to read the Akathist Hymn to the Virgin Mary, or to sing a canon.
Once the akathist or canon is finished, we continue with the Prayer of the Hours, and then two concluding prayers — one to the Holy Virgin, the other to Christ. A prayer to one’s Guardian Angel is often also added to the end of the service, which is concluded with a short hymn to the Mother of God.
The above is an outline of the service of Small Compline. During Lent, a much longer form of the service is used, known as Great Lent.