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 led to Satan's sin, rebellion, and downfall?
When accused by His enemies before Pilate, how did Christ treat these accusations?
Through what are they to -be sanctified?
Will the Sabbath be observed as a day of worship in the new earth?
Of what did Christ say the Son of man is Lord?
How does James say the rich have treated the just?
Under what condition does the Lord not hear prayer?

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