Saturday and Sunday are terms in English.
In Latin those are “Sabbath day” and “the Lord’s day”.
yup, Sabbath remains on the last day. As Christians we have worshipped the Lord since Apostolic times on the FIRST day of the week
His First Day of the Week is the 16th Day of His 1st month, the 3rd day from His 14th Day, the Day The Passover Lamb finished His work..
That’s what the scriptures teach.
I admit it isn’t what Daniel’s 4th Beast teaches.
But that’s sort of the point..