Vespers (Evening Prayer)
Vespers (the name means "evening") is designed to be recited in the evening, when the day's work is done. It is the Hour that is most often celebrated in church with a lay congregation, both in the Catholic and the Anglican churches: the Anglicans call it Evensong.
With Sundays and solemnities, Christians retain the Jewish custom of starting the day on the evening before. So, for example, Saturday never has Vespers of its own: they are always "First Vespers" of the Sunday following. [Holy Saturday is a unique exception].
The structure of the Hour
Vespers begins with two psalms, followed by a canticle from the New Testament. Many of these canticles were used liturgically by the earliest Christians, some of them even before the Gospels were written down.
A short reading follows. When Vespers is celebrated with a congregation, this reading can be replaced by a longer one.
Then comes the Magnificat, the canticle of praise by Mary at the Annunciation, when she consented to become the mother of God.
Then come prayers and intercessions for the church and for the world.
The Our Father and a concluding prayer bring Vespers to an end.