The book The Time Is At Hand, 1916 edition, page ii, (forward), said:
The Bible chronology therin presented show that the six great 1000 year days beginning with Adam are ended, and that the great 7th Day, the 1000 years of Christ's Reign, began in 1873.
The book The Day of Vengeance (The Battle of Armageddon), 1897, page 621 said:
Our Lord, the appointed King, is now present, since October 1874.
The 1921 book The Harp of God said on page 236:
"The time of the end" embraces a period from 1799 A.D., as above indicated, to the time of the complete overthrow of Satan's empire and the establishment of the kingdom of the Messiah. The time of the Lord's second presence dates from 1874, as above stated. The latter period is within the first named, of course, and in the latter part of the period known as "the time of the end.
In a similar fashion the March 1, 1922 Watch Tower said:
The indisputable facts, therefore, show that the "time of the end" began in 1799; that the Lord's second presence began in 1874.
The book Creation, 1927, pages 294, 295, 298 said:
Twelve hundred and sixty years from 539 A.D. brings us to 1799, which is another proof that 1799 definitely marks the beginning of "the time of the end." From shortly after 1799, the date of the beginning of "the time of the end," we should expect to find an increase of knowledge, particularly with reference to the Bible.
There are two important dates here that we must not confuse, but clearly differentiate; namely, the beginning of "the time of the end" and the beginning of the presence of the Lord. "The time of the end" embraces a period from 1799 A.D. to the time of the complete overthrow of Satan's empire and the establishment of the kingdom of the Messiah. The time of the Lord's second presence dates from 1874 and is during the latter part of the period known as "the time of the end."
The book Prophecy, 1929, pages 65-66, said:
.... the second presence of the Lord Jesus Christ began in 1874 A.D. This proof is specifically set out in the booklet entitled Our Lord's Return.
Peace