Except the fourth commandment, the seventh day Sabbath was given at creation. See Genesis. So it was never a “shadow” pointing to Christ. You are confusing the annuals sabbaths given to the Jews. The Seventh day Sabbath was “made for man” and instituted at creation.......thousands of years before any Jew. Christ upheld the Sabbath and it’s meaning everytime he was challenged on it.
He never changed it or abrogated it. He simply threw out the man made petty rules the Pharisees had made for it......but he never threw the baby out with the bathwater.......
And Peter says that one day with the LORD is as a thousand years.... So that means the 7th day of creation the Heavenly Father rested one day to Him, but a thousand years to us.
Sabbath means 'rest'. And the law of remembrance was given to the children of Israel/Jacob after they were lead out of bondage establishing the Heavenly Father's form of government. And there are twelve tribes not one.
Genesis 1:14 And God said, "Let there be light in the firmament of the heaven to divide the day from the night; and let them be for sign, and for seasons, and for days, and years.
You think the Heavenly Father did not recognize the 'light' of the sun being the Light of the Son, even when this took place?
There are prophesies given in months and there are prophesies given in 'days'. The 'sun' is reliable to count days wherein the moon is not.