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 cheering message has Christ sent to His people touching His resurrection?
Can there be sin where there is no law?
BY whom was the Ten Commandment law proclaimed?
19. How will Christ's coming overtake those evil servants who say in their hearts, \"My Lord delays His coming\"?
How does Isaiah speak of the wicked at this time?
How must one ask in order to receive?
Who does David say have most now?

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