This passage basically tells us that a Jerusalem council led by the apostles was organized to discuss “this question … this matter” of “circumcision” and “the law of Moses” (Acts 15:1, 2, 5). The Sabbath itself was not debated or even discussed.
The Church decided that the Gentiles were “saved … through the grace of the Lord Jesus Christ” (Acts 15: 11) and thus they did not need to be circumcised. Yet to avoid offending the Jews, they were given certain restrictions: “Therefore I judge that we should not trouble those from among the Gentiles who are turning to God, but that we write to them to abstain from things polluted by idols, from sexual immorality, from things strangled, and from blood” (Verses 19, 20).
It is important to note that in Acts 15:21 believing Gentiles were still worshiping with the Jews in their synagogues “every Sabbath day.” Thus, showing that the “Sabbath day” was not abrogated by the Jerusalem council. Rather, it was reiterated without dissent as the biblical day of worship for both Jews and Gentiles.