Acts 20:7 On the first day of the week we came together to break bread. Paul spoke to the people and, because he intended to leave the next day, kept on talking until midnight.
1 Corinthians 16:2, On the first day of every week, each one of you should set aside a sum of money in keeping with your income, saving it up, so that when I come no collections will have to be made.
Colossians 2:16-17, 16 Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day. 17 These are a shadow of the things that were to come; the reality, however, is found in Christ.
These show that, even during New Testament times, the Sabbath is no longer binding and that Christians are to worship on the Lord’s day, Sunday, instead.
Remember Gal. 5:1-6It is for freedom that Christ has set us free. Stand firm, then, and do not let yourselves be burdened again by a yoke of slavery. 2 Mark my words! I, Paul, tell you that if you let yourselves be circumcised, Christ will be of no value to you at all. 3 Again I declare to every man who lets himself be circumcised that he is obligated to obey the whole law. 4 You who are trying to be justified by the law have been alienated from Christ; you have fallen away from grace. 5 For through the Spirit we eagerly await by faith the righteousness for which we hope. 6 For in Christ Jesus neither circumcision nor uncircumcision has any value. The only thing that counts is faith expressing itself through love. ==
"But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Savior on the same day rose from the dead"
"Hence it is not possible that the [day of] rest after the Sabbath should have come into existence from the seventh [day] of our God. On the contrary, it is our Savior who, after the pattern of his own rest, caused us to be made in the likeness of his death, and hence also of his resurrection" (Commentary on John 2:28 [A.D. 229]).
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The Sabbath remains, yet as Jesus' in the patterm of his own rest was resurrected on a Sunday, we worship on Sunday -- the sabbath is not replaced
Just because the Apostles came together on Sunday to break bread doesn't mean the worship day was changed to Sunday. That's as plain as I can make it. If God wrote it in the Commandments, how can you possibly think one verse changes everything? It doesn't matter what day of the week First Fruits landed on in the Gregorian calendar, it's always First Fruits on the Hebrew calendar. Jesus kept the Hebrew calendar.