The medieval English name for the office of VespersVespers (From Greek esperinos and Latin vesper 'evening') An evening prayer service. (see Divine OfficeDivine Office As outlined in the monastic Rules, the Office consisted of the Night Office (Matins) together with seven hours (times) of prayer during the day: Lauds (at dawn), Prime (first hour of the day), Terce (third hour), Sext (sixth hour), None (ninth hour), Vespers (at dusk), Compline (before bed). This pattern was inspired by the words of the Psalmist: 'I rose at midnight to give praise to thee... Seven times a day I have given praise to thee' Psalms 119 (Vul.118): 62, 164. The major component of these services was the singing of the Psalms. The Office is also known as the Opus Dei (Work of God).). Used in the 1549 Book of Common Prayer for the service which later prayer books call Evening Prayer