"The Bible does not recognize two weekly Sabbaths, one in the Old Testament, to be observed on the seventh day of the week, and one in the New Testament, to be observed on the first day of the next week.
*The Sabbath of the Old Testament is the Sabbath of the New Testament.
On the seventh day of the first week of time God rested from the work of creation.
--This He did not do on any other day of that week.
--He sanctified the very day of His rest. That is, He set it apart to a holy use.
--This He did not do with regard to any other day of the week."
James White