For one thing, keeping the Sabbath is not binding on Gentiles, and most Christians are Gentiles.
If I recall correctly, Acts (chapter 15) describes a serious point of contention between the followers of Paul and a sect of Christian Pharisees, whether Christians were obligated to continue following the Jewish Law. If I recall, the decision was reached that the Law was still binding on Jewish Christians but not Gentile Christians.
So, unless you are a Jewish Christian, keeping the Sabbath is not a requirement at all, and so you are free to take any day off or none.
But government...is not simply the way we express ourselves collectively but also often the only way we preserve our freedom from private power and its incursions. --
Bill Moyers (quoting John Schwarz)