I’ve only proven that you base your belief on the consistency of the Jewish practice, not Scripture. The ONLY reason you chose Saturday is because of the Jewish Sabbath.
Which is fine as long as you realize you aren’t standing on holy ground. The Sabbath is what is important (kinda) and not the day itself.
As long as you’re clear that you’re denying the fact that God beat into them which day it was and the fact they’ve been faithful on that point, I’m fine with it. :)