I don’t understand what a feast is and how does the church “celebrate” feasts… I’m confused with all the terms like feasts, solemnities, commemoration, veneration, celebration…
Can anyone help explain these and make some sense out of them?
“Feasts” is sometimes used in a general way to indicate any saints day. Thus we speak about the feast of St. Patrick, the feast of St. Joseph, the feast of Our Lad of X, and so forth.
In the calendar, each saint and day is assigned a “rank”. The reason for this is due to the overlapping of cycles.
- The fixed cycle: The church has a fixed cycle consisting of feasts that fall on the same calendar day every year- e.g. Aug 15 is Assumption, Dec 25 is Christmas, Jan 1 is the Mother of God, December 7 is St. Ambrose and so on.
- the moveable cycle: this consists of both a few feasts and days in particular seasons. So for example, feasts like Easter, Pentecost, Ascension, Corpus Christi, Sacred Heart and so forth. The seasons like Eastertide and Lent are also moveable.
Because these two cycles overlap, we need to know which day to observe liturgically. For e.g. if St. X coincides with Easter, what do we do? For this reason we have ranks for feasts.
“Solemnity” is the highest rank given to only the most special feasts of Jesus, Mary and the saints. Solemnities are distinguished liturgically in mnay small ways- for exmaple, you can say the Gloria as you do for Sunday Mass. They also begin the evening before. Some solemnities include Christmas, Assumption, the feast of Ss. Peter and Paul, and the feast of the patron saint of your church.
“Feasts” is the term given to the feasts that the Church wishes to highlight but which are not so important as “Solemnities”. Examples are things like the Birthday of the BVM (Sept 8) or the Holy Cross (Sept 14).
“Memorial” is the term given to all other saints days and feasts. It can be either “obligatory” which means the saint must be celebrated on that day, or it can be “optional” - you can choose whether you want ot celebrate it or not.
“Feria” - a feria is a weekday on which, usually, no saints’ days are observed. Thus, sometimes people might say “the feriae of Lent”- they are talking about weekdays in Lent. “Feriae” in the weekdays of Advent, Lent and Easter have their own special Mass. “Feriae” in Ordinary Time do not have a special Mass but have special readings from the lectionary.
“Commemoration” is remembering one feast/day while celebrating another, when two feasts/days overlap.
e.g. In this past Lent, some saints had their feasts. Because Lent is a penitential time, the church gives the option of whether to celebrate the feasts- expressions of joy- or not. When we do observe them, they are “commemorated”. What this means is that though the Mass may be of the day in Lent, we remember the saint by saying his Opening Prayer (Collect). In the Divine Office, we add an antiphon and prayer at the end to remember the saint.
Commemorations are allowed only in Lent, and from Dec 17-24. At all other times, when two days/feasts coincide, we celebrate one and omit the other. If the one to be omitted has the rank of “Solemnity” we do not omit it, but transfer it to another day.
The order to be followed (i.e. which day is higher) can be found in the
Table of Precedence (click on table of liturgical days under Chp 2)
“commemoration” can also be used in a looser way to refer to remembering someone at Mass by mentioning their name during a prayer (usually the Eucharistic Prayer). So for example, we may say that the priest commemorated the BVM that means he used her name during the Eucharistic Prayer. Or he commemorated the Pope, or my late uncle, or the bishop.
“Veneration” expresses the honour that we pay to the saints or the BVM or their images, relics, etc. by treating them with reverence. For example, kissing a holy picture, lighting a candle in front of it or having a Mass said in honour of a particular saint is an expression of the the “veneration” that we pay to that saint.
We may also use “veneration” to distinguish theologically the prayers we pray to the saints and those to God. The Trinity may be said to receive our “adoration” (the Latin word is latria) and the saints our “veneration”. (dulia) Mind you, this is a bit sketchy because “adoration” is not as specific as “latria” tough it is now often being used that way.
“celebration” is what you do when you win the lottery.

“Celebration” can be used in many ways.
- We can use it to speak of observing special feasts and joyous occasions. So we often say we celebrate Easter, or celebrate Christmas.
- Nowadays, we refer to liturgical events as “liturgical celebrations”. In one sense, celebration is used to refer to a carrying out of the rites and ceremonies. In another sense, all the sacraments are joyous events of thanksgiving of the Church to God for his graces and so we may say truly that we “celebrate” them. Moreover they are usually celebrated in the context of the Church as a community. Even if only two people are present, certainly many members of the heavenly Church - angels and saints - are all present.