The Daily Office of the Church developed from the daily round of prayer said in monastic communities for centuries. Monks and nuns prayed seven times in every 24-hour period. To make daily prayer accessible for everyone, whether lay or ordained, the Prayer Book distills these offices of prayer down to two: Morning Prayer (also called Matins) and Evening Prayer (also called Evensong, whether it’s sung or not).
Evening Prayer is said Monday through Friday in the Lady Chapel (unless otherwise announced).