A fixed day of the week

"And, when the Sabbath was on a fixed seventh day, and on a fixed day of the week, that is plainly to admit nothing else than that the creation Sabbath was on a fixed seventh day of the week."

A.T. Jones

Thus the heavens and the earth were finished, and all the host of
them. And on the seventh day God ended His work which He had

made; and He rested on the seventh day from all His work which He had made.
And God blessed the seventh day, and sanctified it: because that in it He had rested from all His work which God created and made.
Remember the sabbath day, to keep it holy. For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.
Genesis 2:1-3/Exodus 20:8,11