Days designated for giving special honor to God, to the Saviour, to saints, and to holy things. Some are fixed festivals, each having a certain day of the year assigned to it. Others are movable, occurring earlier or later in different years. Festivals are also divided into
- holy days of obligation – the faithful are required to assist at Mass and abstain from unnecessary servile work
- ordinary festivals – the Church merely observes the feast in her Office and Mass
Festivals are also arranged in three classes, according to their importance
Certain days when the Church does not honor any saint are called ferials (feria, a weekday). Some great festivals have octaves, which extend the solemnity of the feast through eight days; and some have vigils, in which the observance of the feast is begun on the preceding day.