While all of the daily services are properly referred to as the Canonical Hours, when we say ‘The Hours’ we are usually referring to four short services known only by the hours at which they are held; namely, at the first, third, sixth, and ninth hours of the day — roughly corresponding to 6.00am, 9.00am, 12.00pm, and 3.00pm respectively.
They all follow exactly the same structure, reflecting a particular theme relating to the time of day it is intended to be said:
After the usual introductory prayers, each Hour begins with the reading of three Psalms. We then say the apolytíkia of the day, the trisagion prayers, the kontakion of the day, the Prayer of the Hours, and a final concluding prayer.
In practice, these Hours are not usually said at their appointed times, but are appended to other services. The first hour is read at the end of matins, the third and sixth hours are read together (for which reason we often refer to the trithékti, the third-sixth), while the ninth hour is read immediately before vespers.
The First Hour
The first hour of the day corresponds roughly to sunrise, for which reason the primary theme of this service is light — specifically Christ as the ‘True Light which gives light to every man coming into the world’ (John 1:9, cited in the beautiful concluding prayer of the First Hour). Psalms 5, 89, and 100 are read during this Hour.
The Third Hour
We are told in the Book of Acts (2:15) that it was at the third hour of the day that the Holy Spirit descended on the Apostles on the Day of Pentecost. The Holy Spirit, then, is the primary focus of the third hour. Psalms 16, 24, and 50 are read.
The Sixth Hour
The Gospels tell us that, at the Crucifixion of Jesus, ‘there was darkness over all the land from the sixth hour unto the ninth hour’ (Matthew 27:45, Mark 15:33, Luke 23:44), for which reason the Crucifixion is the central theme of the sixth hour. Psalms 53, 54, and 90 are read.
The Ninth Hour
It was at the ninth hour when our Lord ‘breathed His last’ on the Cross and died for our salvation. Christ’s death on the Cross, then, is the primary theme of the ninth hour. We are also told in Acts 3:1 that the ninth hour was the ‘hour of prayer’ when the disciples would go to the Temple. On days of strict fasting, we traditionally abstain from all food until the ninth hour of the day. Psalms 83, 84, and 85 are read.
Mesōria — the Mid-Hours
On certain days during the Advent Fast before Christmas and the Fast of the Apostles in June, we will also read the mesōria (mid-hours) after each of the hours; it is effectively a doubling of each service. The mesōria have exactly the same structure as the services of the hours, but a different set of three Psalms and a different concluding prayer.
At the mesōrion of the of the first hour, we read Psalms 45, 91, 92; at the mesōrion of the third hour, Psalms 29, 31, 60; at the mesōrion of the sixth hour, Psalms 55, 56, 69; at the mesōrion of the ninth hour, Psalms 112, 137, 139.