And he said unto me, Unto two thousand and three hundred days; then shall the sanctuary be cleansed.
Seventy weeks are determined upon thy people and upon thy holy city, to finish the transgression, and to make an end of sins, and to make reconciliation for iniquity, and to bring in everlasting righteousness, and to seal up the vision and prophecy, and to anoint the most Holy.
Know therefore and understand, that from the going forth of the commandment to restore and to build Jerusalem unto the Messiah the Prince shall be seven weeks, and threescore and two weeks: the street shall be built again, and the wall, even in troublous times.And after threescore and two weeks shall Messiah be cut off, but not for Himself:...
Daniel 8:14.9:24-26
"Jeff Pippenger insists that the 2520 prophecy is part of the “prophetic periods” spoken of by Ellen White in Early Writings.
The reasoning is that Ellen White speaks of the “prophetic periods” in the plural and then describes “them” as reaching to 1843/1844.. “Again they were led to their Bibles to search the prophetic periods."
1) Ellen White never once directly mentions the 2520 either in Early
Writings or in any other of her writings. In contrast, there are over 90 direct references to the 2300-day prophecy in the Spirit of Prophecy (SOP).
Writings or in any other of her writings. In contrast, there are over 90 direct references to the 2300-day prophecy in the Spirit of Prophecy (SOP).
2) It is assumed that the use of the phrase “prophetic periods” in Early Writings must be referring to more than just the 2300-day prophecy. Yet this is not the case.
In the book Great Controversy, the term “prophetic periods” is employed more than once to describe the 2300 day-prophecy ONLY, and not the 2300 AND the 2520. In addition, the 2300-day prophecy is consistently described by Ellen White as having “prophetic periods.”
“Seventy weeks, representing 490 years, are declared by the angel to be cut off, as specially pertaining to the Jews. But from what were they cut off? As the 2300 days was the only period of time mentioned in chapter 8, it must be the period from which the seventy weeks 
were cut off; the seventy weeks must therefore be a part of the 2300 days, and the two periods must begin together. The seventy weeks were declared by the angel to date from the going forth of the commandment to restore and build Jerusalem. If the date of this commandment could be found, then the starting point for the great period of the 2300 days would be ascertained” (Great Controversy, p. 326).
“The preaching of a definite time for the judgment, in the giving of the first message, was ordered by God. The computation of the prophetic periods on which that message was based, placing the
close of the 2300 days in the autumn of 1844, stands without impeachment. The repeated efforts to find new dates for the beginning and close of the prophetic periods, and the unsound reasoning necessary to sustain these positions, not only lead minds away from the present truth, but throw contempt upon all efforts to explain the prophecies. The more frequently a definite time is set for the Second Advent, and the more widely it is taught, the better it suits the purposes of Satan..... Those who persist in this error will at last fix upon a date too far in the future for the coming of Christ. Thus they will be led to rest in a false security, and many will not be undeceived until it is too late” (Great Controversy, p. 457).
close of the 2300 days in the autumn of 1844, stands without impeachment. The repeated efforts to find new dates for the beginning and close of the prophetic periods, and the unsound reasoning necessary to sustain these positions, not only lead minds away from the present truth, but throw contempt upon all efforts to explain the prophecies. The more frequently a definite time is set for the Second Advent, and the more widely it is taught, the better it suits the purposes of Satan..... Those who persist in this error will at last fix upon a date too far in the future for the coming of Christ. Thus they will be led to rest in a false security, and many will not be undeceived until it is too late” (Great Controversy, p. 457).
The SOP clearly states that
the 2300-day prophecy has “two periods.”
These statements clearly show plurality in
speaking only of the 2300-day prophecy."
James Rafferty