Yep, you got it right, the Caholic Church changed the day of worship...
Who Made Sunday Holy?
“Written by the finger of God on two tables of stone, this Divine code (ten commandments) was received from the Almighty by Moses amid the thunders of Mount Sinai...Christ resumed these Commandments in the double precept of charity--love of God and of the neighbour; He proclaimed them as binding under the New Law in Matthew 19 and in the Sermon on the Mount (Matthew 5)...The (Catholic) Church, on the other hand, after changing the day of rest from the Jewish Sabbath, or seventh day of the week, to the first, made the Third Commandment refer to Sunday as the day to be kept holy as the Lord’s Day...He (God) claims one day out of the seven as a memorial to Himself, and this must be kept holy...”The Catholic Encyclopaedia, vol. 4, “The Ten Commandments”, 1908 edition by Robert Appleton Company; and 1999 Online edition by Kevin Knight, Imprimatur, John M. Farley, Archbishop of New York.
“Question: How prove you that the church had power to command feasts and holydays?
“Answer: By the very act of changing the Sabbath into Sunday, which Protestants allow of and therefore they fondly contradict themselves by keeping Sunday strictly, and breaking most other feasts commanded by the same church.
“Question: Have you any other way of proving that the church has power to institute festivals of precept?
“Answer: Had she not such power, she could not a done that in which all modern religionists agree with her; -she could not have substituted the observance of Sunday the first day of the week, for the observance of Saturday the seventh day of the week, a change for which there is no Scriptural authority.” Stephen Keenan, A Doctrinal Catechism On the Obedience Due to the Church, 3rd edition, Chapter 2, p. 174 (Imprimatur, John Cardinal McCloskey, Archbishop of New York).
“Perhaps the boldest thing, the most revolutionary change the Church ever did, happened in the first century. The holy day, the Sabbath, was changed from Saturday to Sunday. ‘The day of the Lord’ was chosen, not from any direction noted in the Scriptures, but from the (Catholic) Church’s sense of its own power...People who think that the Scriptures should be the sole authority, should logically become 7th Day Adventists, and keep Saturday holy.” St. Catherine Church Sentinel, Algonac, Michigan, May 21, 1995.
Note: Nto necessarily SDA, but a Sabbatarian at any rate.
“Nowhere in the Bible is it stated that worship should be changed from Saturday to Sunday...Now the Church...instituted, by God’s authority, Sunday as the day of worship. This same Church, by the same divine authority, taught the doctrine of Purgatory long before the Bible was made. We have, therefore, the same authority for Purgatory as we have for Sunday.” Martin J. Scott, Things Catholics Are Asked About, 1927 edition, p. 136.
“Question - Which is the Sabbath day?
“Answer - Saturday is the Sabbath day.
“Question - Why do we observe Sunday instead of Saturday?
“Answer - We observe Sunday instead of Saturday because the Catholic Church, in the Council of Laodicea (A.D. 364), transferred the solemnity from Saturday to Sunday.” Peter Geiermann, C.S.S.R., The Convert’s Catechism of Catholic Doctrine, p. 50, 3rd edition, 1957.
“Is Saturday the seventh day according to the Bible and the Ten Commandments? I answer yes. Is Sunday the first day of the week and did the Church change the seventh day - Saturday - for Sunday, the first day? I answer yes. Did Christ change the day’? I answer no!”
“Faithfully yours, J. Card. Gibbons.” James Cardinal Gibbons, Archbishop of Baltimore, Md. (1877-1921), in a signed letter.
“Question. - How prove you that the Church hath power to command feasts and holy days?
“Answer. - By the very act of changing Sabbath into Sunday which Protestants allow of; and therefore they fondly contradict themselves, by keeping Sunday strictly, and breaking most other feasts commanded by the same Church.
“Question. - How prove you that?
“Answer. - Because by keeping Sunday, they acknowledge the Church’s power to ordain feasts, and to command them under sin: and by not keeping the rest by her commanded, they again deny, in fact, the same power.” An Abridgment of the Christian Doctrine, composed by Henry Tuberville, p. 58.
“Some theologians have held that God likewise directly determined the Sunday as the day of worship in the New Law, that He Himself has explicitly substituted the Sunday for the Sabbath. But this theory is now entirely abandoned. It is now commonly held that God simply gave His Church the power to set aside whatever day or days she would deem suitable as Holy Days. The (Roman Catholic) Church chose Sunday, the first day of the week, and in the course of time added other days as holy days.” John Laux, A Course in Religion for Catholic High Schools and Academies, 1936 edition, vol. 1, p. 51.
“Question. What warrant have you for keeping Sunday preferably to the ancient sabbath which was Saturday?
“Answer. We have for it the authority of the Catholic church and apostolic tradition.
“Question. Does the Scripture anywhere command the Sunday to be kept for the Sabbath?
“Answer. The Scripture commands us to hear the church (St.Matt.18:17; St. Luke 10:16), and to hold fast the traditions of the apostles. 2 Thess 2:15. But the Scripture does not in particular mention this change of the Sabbath.
“St John speaks of the Lord’s day (Rev 1:10) but he does not tell us what day of the week that was, much less does he tell us what day was to take the place of the Sabbath ordained in the commandments. St.Luke speaks of the disciples meeting together to break bread on the first day of the week. Acts 20:7. And St. Paul (1 Cor.16:2) orders that on the first day of the week the Corinthians should lay in store what they designated to bestow in charity on the faithful in Judea: but neither the one or the other tells us that this first day of the week was to be henceforth a day of worship, and the Christian Sabbath; so that truly the best authority we have for this ancient custom is the testimony of the church. And therefore those who pretend to be such religious observers of Sunday, whilst they take no notice of other festivals ordained by the same church authority, show that they act more by humor, than by religion; since Sundays and holidays all stand upon the same foundation, namely the ordinance of the (Roman Catholic) church.” Catholic Christian Instructed, 17th edition, p. 272-273.
“Protestantism, in discarding the authority of the (Roman Catholic) Church, has no good reasons for its Sunday theory, and ought logically to keep Saturday as the Sabbath.” John Gilmary Shea, American Catholic Quarterly Review, January 1883.
“The Catholic church for over one thousand years before the existence of a Protestant, by virtue of her divine mission, changed the day from Saturday to Sunday...The Protestant World at its birth found the Christian Sabbath too strongly entrenched to run counter to its existence; it was therefore placed under the necessity of acquiescing in the arrangement, thus implying the (Catholic) Church’s right to change the day, for over three hundred years. The Christian Sabbath is therefore to this day, the acknowledged offspring of the Catholic Church as spouse of the Holy Ghost, without a word of remonstrance from the Protestant World.” James Cardinal Gibbons in the Catholic Mirror, September 23, 1983.
Note: In referring to the Christian Sabbath, this is a euphemism for Sunday.