The Second Vatican Council says:
“[T]he Lord’s day is the original feast day […]. Other celebrations, unless they be truly of greatest importance, shall not have precedence over the Sunday which is the foundation and kernel of the whole liturgical year.”
I totally agree. The fact that it is Sunday is the most important reason to gather together for a Sunday liturgy. It does not need any other reason. The Sunday itself has a theological meaning – such as the Sabbath, although Christians today do not follow the Old Testament rules for the Sabbath anymore.
Nevertheless there are occasions when the Roman Catholic liturgy is celebrated on a Sunday, although it is not the Sunday which is celebrated. As the Council said: “Other celebrations, unless they be truly of greatest importance, shall not have precedence over the Sunday”.
The “ordinary Sunday” should be the clear framework of the liturgical year. Maybe the most important aspect of that framework – as we have it since 1969/70 – is the course reading of one Gospel per year step by step in a three-year cycle: Matthew, Mark, and Luke (while John is mainly read on other “celebrations of greatest importance”). If you know that and hear the Council’s words but do not know anything about the Roman Catholic calendar, you might think that about 45 or even more Sundays per year are “ordinary,” following this rule.
But that is not the case. The Roman calendar provides a ranking of 13 different degrees of feast days, among which the Sundays in ordinary time are no higher than on rank 6.
There are special Sundays in Lent (six Sundays) and Easter time (eight Sundays, both on rank 2). These Sundays should be no major problem: At least they are clearly directed to the mystery of Easter which is the very source of the Christian Sunday itself, even if they do not have the course reading of the Gospel. But there are also four Sundays in Advent (rank 2) which do not so clearly direct to the mystery of the Sunday but rather to Christmas. Let us accept this as a sign of importance of the Incarnation. With respect to Advent, Christmas, Lent, and Easter time, the Roman calendar does not count more than 34 ordinary weeks per year.
But there is more. Whenever a solemnity (rank 3 or 4) falls on a Sunday, we celebrate the liturgy of the solemnity, not of the Sunday: Biblical readings, collect, preface, even the color of the vestments is determined by the solemnity, not the Sunday. The community gathers on Sunday, but they do not celebrate the Sunday. Depending on your diocese or order, the number of solemnities with fixed calendar dates might vary a bit, but in every year there are probably around 2 solemnities falling on Sundays. So we are down to 32 ordinary Sundays.
But there is more. Two solemnities (rank 3/4) and one feast day of the Lord (rank 5) are always on Sundays: Baptism of the Lord (Sunday after January 6), Sunday of Trinity (Sunday after Pentecost), and Christ the King (34th Sunday of Ordinary Sunday). So we are down to 29.
But there is more (at least in certain regions of the world following precisely the liturgical law of the Roman or diocesan calendar). If Epiphany (January 6) is not a public holiday it is postponed or preponed to the nearest Sunday. Ascension of the Lord and Corpus Christi are postponed to the following Sunday (regularly on Thursday). Same for the patron saint of the diocese and the patron saints of the parishes. We are down to about 25 ordinary Sundays or less.
But there is more (at least here in Austria, maybe your experience in America is different). Pope and bishops have told us to dedicate certain Sundays to certain “themes”: God’s mercy, prayer for vocations, prayer for the missionaries, Thanksgiving. There is the Sunday for the First Communion, maybe a Sunday for Confirmation. Some parishes celebrate wedding anniversaries on a certain Sunday, etc. These occasions do not necessarily require a new collection of Biblical readings, collects, and so on, but at least they focus the community’s thoughts on other aspects than just the mystery of the Sunday. It is more than realistic to calculate that some parishes celebrate “pure Sundays” not more often than only 15 or 20 times a year.
There might be good and comprehensible reasons for every single of these mentioned cases. But on the whole this development is not helpful. It looks as if Sunday alone is not reason enough for Christians to gather for Eucharist. It looks as if we always need a special theme or a special event as a reason to go to church.
As a person with certain bureaucratic tendencies I often start to design new rules for the Roman calendar that seem more reasonable to me than the actual Roman calendar does. But after a while I start to believe that the problem does not lie with liturgical law. Somewhere deep in our hearts, in our proclamation of faith, and in our spiritual culture we have lost what the Jews have perpetuated in their experience of the Sabbath: that the Sabbath itself is a liturgy of freedom that gives order and meaning to the entire life. The Sabbath does not need to be exceeded or outperformed. It carries its overwhelming meaning in itself. The same should be true for the Christian Sunday, but it is not. Maybe it has not been for many centuries.
So I do not have a precise plan (except creating better rules that no one would follow…), but I see an urgent concern in the Catholic Church: Save Sunday.