When is the Sabbath?

Remember the sabbath day, to keep it holy.  Six days shalt thou labour, and do all thy work:  But the seventh day is the sabbath of the Lord thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates:  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. Exodus 20:8‭-‬11 KJV

What should you be doing in this day after we have well rested?

And the next sabbath day came almost the whole city together to hear the word of God. Acts 13:44 KJV

And two parts of all you that go forth on the sabbath, even they shall keep the watch of the house of the Lord about the king. 2 Kings 11:7 KJV

And he was teaching in one of the synagogues on the sabbath. Luke 13:10 KJV

Who is the for?

And he said unto them, The sabbath was made for man, and not man for the sabbath: Mark 2:27 KJV