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.

For what purpose did Christ come into the world?
What did Moses set forth as the basis of righteousness?
Through what was Christ made a complete and perfect Saviour?
8. Did God bless and sanctify the seventh day while He was resting upon it, or when His rest on that day was past?
How much power will this beast exercise?
How, according to Luke, did Christ answer this question?
What is God's attitude toward the poor?

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