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.

How was Christ's first advent to be heralded?
What record answers to this prophecy?
In whom has God made us accepted?
What did Jesus say the Spirit of truth would do?
What will happen if a child is not properly instructed?
What description does the prophet Jeremiah give of the earth during this time?
What does He say of the teachings of enchanters and sorcerers?

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