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 gives victory in our conflicts with the world?
What is the duty of every child?
What message has God commissioned His ministers to bear to men?
26. When Israel had apostatized, and were almost universally worshipping Baal, what appeal did Elijah make to them?
What did John say was to be the end of this beast?
What question does Job ask and answer?
What encouragement does Jesus give us to meet cheerfully the troubles and trials of life?

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