OK, since you insist the "first day" meeting of Acts 20 is "implicit proof" of Sunday sacredness, let's check with
www.Romeschallenge.com and see if your church agrees with you:
"Once more, the Biblical apologists for the change of day (change of the Sabbath from the 7th day to the 1st day) call our attention to the Acts, chapter 20, verses 6 and 7; "And upon the first day of the week, when the disciples came together to break bread." etc. To all appearances the above text should furnish some consolation to our disgruntled Biblical friends, but being a Marplot, we cannot allow them even this crumb of comfort. We reply by the axiom: "Quod probat nimis, probat nihil"--"What proves too much, proves nothing." Let us call attention to the same, Acts 2:46; "And they, continuing daily in the temple, and breaking bread from house to house," etc. Who does not see at a glance that the text produced to prove the exclusive prerogative of Sunday, vanishes into thin air--an ignis fatuus--when placed in juxtaposition with the 46th verse of the same chapter? What the Biblical Christian claims by this text for Sunday alone the same authority, St. Luke, informs us was common to every day of the week; "and they, continuing daily in the temple, and breaking bread from house to house."
I will let the Vatican know that one of their most loyal apologists - you, Dead Bread - fails to "see at a glance" that Acts 20 is no proof at all for Sunday sacredness - axplicit, explicit, implicit, oxplicit, or uxplicit