What day of the week is the Sabbath? this is a question i believe has caused divisions across christianity.
The answer may be hidden in Genesis 1v14-19
14. And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:
15.And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
16.And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
17.And God set them in the firmament of the heaven to give light upon the earth,
18. And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good.
19. And the evening and the morning were the fourth day.
The first full moon was on the fourth day since beginning of creation. and on the third day after the first full moon, God rested from all his work: that is on the seventh day. The lunar cycle is 29.53059 days, and since time memorial the third day after every new full moon has been on every single day. Arguments that the moon may have been on a different phase do not make a difference. whatever moon phase that might have been when God rested on the seventh day, the same moon phase has been on every day of the week. Now the third day after creation of the sun and moon is the Sabbath. The third day after the first sun and the first new moon is the Sabbath.
7. Therefore God again set a certain day, calling it Today, when a long time later he spoke through David, as was said before:
"Today, if you hear his voice, do not harden your hearts."
8. For if Joshua had given them rest, God would not have spoken later about another day.
9. There remains, then, a Sabbath-rest for the people of God;
10. for anyone who enters God's rest also rests from his own work, just as God did from his.
11. Let us, therefore, make every effort to enter that rest, so that no one will fall by following their example of disobedience.
'Today' not wednesday,thursday,friday,saturday,sunday,monday,tuesday.
Now we who have believed enter that rest, just as God has said