In the Western churches periodic reforms of the church year have occurred, notably in the Reformation era and again in the 20th century. The Protestant reformers of the 16th century took differing attitudes toward such reforms. With their strong sense of the prime authority of Scripture and of the freedom of the gospel from all legalisms in liturgical matters, they revised the church year with varying degrees of radicalism. Lutherans and Anglicans took a conservative position, retaining the traditional seasons but eliminating commemorations that had no connection with the biblical record.

The Reformed churches, on the other hand, allowed only those feasts with a clear basis in the New Testament: Sundays, Holy Week and Easter, Pentecost, and in some cases Christmas. The Church of Scotland and Anabaptist and Puritan groups abolished the church year entirely, except for Sundays. In recent years this attitude has been very much modified. Their protest has been a reminder to the church that all days are regarded as belonging to Christ in the freedom of his Spirit, who cannot be controlled by rigid systems of fixed special observances.

In the late 20th century in the Western churches the church year was being subjected to an overall revision comparable in scope only to that of the 16th century. This was due to a number of currents of interest that were converging; i.e.—advances in historical and liturgical studies, changes in theological perspectives, and ecumenical encounters.

The basic structure of the church year was the creation of the ancient churches in the varied cultures surrounding the Mediterranean Sea that were embraced in the Roman Empire. Christian missionaries have carried the church year throughout the world—first in the Northern Hemisphere and, since the 16th century, in the Southern Hemisphere, where the natural seasons are reversed. It is unlikely that the dates of the two major feasts, Easter and Christmas, which control the seasons of the church year, will be changed. But new symbols and popular customs associated with them will emerge in areas where, for example, Easter is celebrated in the autumn rather than as a spring festival.

The church year consists of two concurrent cycles: (1) the Proper of Time (Temporale), or seasons and Sundays that revolve around the movable date of Easter and the fixed date of Christmas, and (2) the Proper of Saints (Sanctorale), other commemorations on fixed dates of the year. Every season and holy day is a celebration, albeit with different emphases, of the total revelation and redemption of Christ, which are “made present at all times” or proclaim “the paschal mystery as achieved in the saints who have suffered and been glorified with Christ” (Second Vatican Council, “Constitution on the Sacred Liturgy”). The church year is an epitome in time of the history of salvation in Christ.