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 is the final result or fruit of sin?
What does the sorrow of the world do?
How did Abraham respond to this command?
What is said of the poor but wise child?
To whom do those things which are revealed belong?
22. How did He manifest His sympathy in the case of Mary and her friends weeping over the death of Lazarus?
Who has everlasting life?

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