Do Protestant writers acknowledge the same?

Answer

They do.
NOTE - "IS there no express commandment for observing the first day of the week as Sabbath,
instead of the seventh day?-None whatever. Neither Christ, nor His apostles, nor the first Christians
celebrated the first day of the week instead of the seventh as the Sabbath."-New York Weekly Tribune,
May 24, 1900.
"The Scriptures nowhere call the first day of the week the Sabbath. . . . There is no Scriptural
authority for so doing, nor of course any Scriptural obligation." The Watchman (Baptist).
"The observance of the first instead of the seventh day rests on the testimony of the church, and
the church alone.' -- Hobart Church News, July 2, 1894.
For additional testimonies, see reading on page 146.

What was one direct purpose of the incarnation of Christ?
29. What bears witness to the genuineness of the righteousness obtained by faith, apart from the deeds of the law?
Just before the fall of Babylon, what did her king do?
Who is this dragon said to be?
What trying experience did Christ then foretell?
What shows that the angels sent to Abraham and Lot were real beings?
Does God willingly afflict the children of men?

Questions & Answers are from the book Bible Readings for the Home Circle