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 different results attend the covering and the confessing of sins?
What are children declared to be?
What did this power do to the truth?
Did Christ come to abolish or to destroy the law?
How does Paul describe this dedication of the covenant?
What has He commanded men to observe in memory of this great work?
12. What was the appearance of the angel that rolled away the stone from the sepulchre at the resurrection of Christ?

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