You can't be serious. The Sabbath was established at Creation and the lives of Adam, Methuseleh, Shem and Abraham overlapped hundreds of years. The Hebrews knew when the Sabbath was after they left Egypt and before the Mt. Sinai event. All of the prophets knew when it was. Jesus never corrected the day of the week. God commanded worship is due Him on the Sabbath but left us no way to know what day that really is? That sounds like desperation on your part.
Bipolar, Ezekiel 46:1 shoots the 7 same days since Creation theory to bits..
His months have a day, at the head of each month, that isn’t His 6 work days or His 7th Day Sabbath..
Israel doesn’t follow it today.
To their blindness..
Sounds like you can’t actually answer the question.