That's not what it means at all. The seventh day, the sabbath, was part of the ONLY written record they had.
God made the 7th day holy and rested as an example to his people:
Gen 2:1 Thus the heavens and the earth, and all the host of them, were finished.
Gen 2:2 And on the seventh day God ended His work which He had done, and He rested on the seventh day from all His work which He had done.
Gen 2:3 Then God blessed the seventh day and sanctified it, because in it He rested from all His work which God had created and made.
And Exodus 20 tells us why it was created for man:
Exo 20:8 "Remember the Sabbath day, to keep it holy.
Exo 20:9 Six days you shall labor and do all your work,
Exo 20:10 but the seventh day is the Sabbath of the LORD your God. In it you shall do no work: you, nor your son, nor your daughter, nor your male servant, nor your female servant, nor your cattle, nor your stranger who is within your gates.
Exo 20:11 For in six days the LORD made the heavens and the earth, the sea, and all that is in them, and rested the seventh day. Therefore the LORD blessed the Sabbath day and hallowed it.
It wasn't changed. It was the same holy 7th day.
Mark chapter 2 concerns extra rigid rules imposed on the Sabbath by the Pharisees...so strict that a hungry man couldn't eat grain off the bush because it was like "work". A whole bunch goes into it...hypocrisy, judgementalism, etc etc..
He then makes his point:
Mar 2:27 And He said to them, "The Sabbath was made for man, and not man for the Sabbath.
The sabbath was made for man to enjoy and relax...NOT to get in trouble for following hypocritical rules.
And THEN he puts the final stamp on it:
Mar 2:28 Therefore the Son of Man is also Lord of the Sabbath."
He tells them he IS the Lord who MADE the sabbath so it's God's authority over the sabbath and not the Pharisees.
However he NEVER denigrates, puts down, or alters the sabbath. Your viewpoint is simply a viewpoint used by modern Christianity to get away from observing God's sabbath.