A prefeast (also known as forefeast) is a period of time preceding certain major feasts of the Christian year during which the Church anticipates the approaching Feast. The liturgical life of the Church reflects this anticipation by foreshadowing the feast in the divine services leading up to the Nativity.

This service is a combination of Vespers (evening prayers) and Compline (final service of the day, before sleep) and incorporates beautiful hymnography to prepare us for the birth of Christ.