Basically the Hours are a series of short services which corresponds to the four watches of the day.

The early Christians continued the ancient Jewish practice of reciting prayers at certain times of the day or night. In the Psalms we find expressions like “In the morning I offer thee my prayer”; “At midnight I will rise and thank thee”; “Evening, morning and at noonday will I praise thee”; “Seven times a day I will praise thee”; etc. The Apostles observed the Jewish custom of praying at the first, third, sixth and ninth hour, as well as at midnight (Acts 10:2-3, 9; 16:25).

The Hours themselves are four relatively brief prayer services from the Daily Cycle of Worship that mark the principal periods of the day.

• First Hour (6:00 – 9:00 a.m.) commemorates Christ before Pilate
• Third Hour (9:00 – noon) commemorates Pilate’s judgment of Christ
• Sixth Hour (noon – 3:00 p.m.) commemorates the Crucifixion
• Ninth Hour (3:00 – 6:00 p.m.) commemorates the death of Christ upon the Cross

Each of these services, which are comprised primarily of Psalms, can be found in the Book of Hours (Horologion in Greek or Chasoslov in Slavonic).