The interpretation of the 1,290 days and 1,335 days of Daniel 12: 11, 12 as 1,290 years and 1,335 years respectively can be found already among the Jewish expositors of the eighth century A.D. This interpretation, based on the year-day principle (see Num 14:34; Ezek 4:6, 7), continued to be advocated by the followers of Joachim of Floris (1130-1202), as well as by several other expositors during the pre-Reformation, the Reformation, and the subsequent Protestant tradition.
William Miller (1782-1849), on his turn, believed (1) that both the 1,290 years and the 1,335 years had began in A.D. 508, with Clovis's victory over the Arian Visigoths, which was a decisive step in uniting both political and ecclesiastic powers for Medieval Catholicism to be able to punish the "heretics"; (2) that the 1,290 years were fulfilled in 1798, with the imprisonment of Pope Pius VI by the French army; and (3) that the 1,335 years would extend for 45 years more, until the end of the 2300 years of Daniel 8:14 in 1843/1844. This interpretation was kept by early Sabbatarian Adventists,  becoming the historical position of the Seventh-day Adventist Church up to our own days. 
But in more recent years some independent preachers started to propagate a "new light" on the 1,290 and 1,335 days of Daniel 12. Rejecting the traditional Adventist understanding, such individuals claim that both time-periods comprise "literal" days (and not days which represent "years") to be fulfilled still in the future. Some of them suggest that both periods will begin with the future national Sunday law; that the 1,290 "literal" days are the time-period reserved for God's people to leave the cities; and that at the end of the 1,335 "literal" days the voice of God will announce the "day and hour" of Christ's second coming.
As interesting as this theory might be, there are at least five basic reasons which do not allow us to accept it.
1. This theory is based on a partial and biased reading of the Spirit of Prophecy.
One of the arguments used to justify the theory of the future fulfillment of the 1,290 and 1,335 days is the false claim that Ellen White regarded as erroneous the notion that the 1,335 days were already fulfilled in the past. Allusions are made to Mrs. White letter "to the Church in Bro. Hastings house," dated as November 7, 1850, in which are mentioned some problems related to Brother O. Hewit, of Dead River. In the original text of this letter appears the following statement, "We told him of some of his errors in the past, that the 1,335 days were ended and numerous errors of his." 
Some advocates of the "new prophetic light" argue that the conjunction "that" should be understood in the above-quoted statement as bearing the meaning of "such as.'' So they are able to make the sentence say that among the errors Hewit held was the idea "that the 1335 days were ended."
If Ellen White's intention was really to correct Brother Hewit for believing that the 1,335 days were already fulfilled, then we are left with the following questions: Why did Ellen White limit herself to correct, in 1850, in a partial and biased form, only the personal position of that brother, without any rebuke to other Adventist leaders who also believed that this prophetic period was already fulfilled in 1844? Why did she not reprove her own husband (James White) who stated in the Review, still in 1857, that "the 1,335 days ended with the 2,300, with the Midnight Cry in 1844"? Why did she not reprove him for continuing to publish in the Review several articles of other authors advocating the very same idea?  And more, how could Ellen White declare in 1891 that "there will never again be a message for the people of God that will be based on time"  if the fulfillment of the 1,290 and 1,335 days were still in the future?
Evidences that Ellen White believed that those prophetic periods were already fulfilled in her own days can be found also in her statements saying that Daniel was already being vindicated in his lot (see Dan 12:13) since the beginning of the time of the end.  Thus, it seems evident that P. Gerard Damsteegt, Professor of Church History at the Theological Seminary of Andrews University, was correct when he declared that "already in 1850 E. G. White had written that 'the 1,335 days were ended,' without specifying the time of their completion." 
2. This theory breaks the prophetic-literary parallelism of the book of Daniel.
In order to justify the alleged future fulfillment of the 1,290 and 1,335 days, the advocates of this "new prophetic light" claim without any constraint that the content of Daniel 12:5-13, where those time-periods are mentioned, is not part of the prophetic chain of Daniel 11. Yet, a more careful analysis of the literary structure of the book of Daniel does not confirm this theory.
William H. Shea explains that in the book of Daniel each prophetic period (1,260, 1,290, 1,335, and 2,300 days) appears as a calibrating appendix to the basic body of the respective prophecy to which it is related. For instance, the vision of chapter 7 is described in verses 1-14, but the time related to it appears only in verse 25. In chapter 8, the body of the vision is related in verses 1-12, but the time appears only in verse 14. In a similar way, the prophetic time-periods related to the vision of chapter 11 are only mentioned in chapter 12.
Such parallelism confirms that the 1,290 days and the 1,335 days of Daniel 12:11, 12 share the same prophetic-apocalyptic nature of "a time, two times, and half a time" of Daniel 7:25 (RSV), and of the 2,300 "evenings and mornings" of Daniel 8:14 (RSV). So, if we apply the year-day principle to the prophetic periods of Daniel 7 and 8, we should also apply it to the time-periods of Daniel 12, for all these time-periods are in someway interrelated between themselves, and the description of each vision points only to a single fulfillment of the prophetic time-period related to it.
Besides this, the allusion in Daniel 12:11 (NIV) to the "daily sacrifice" and the "abomination that causes desolation" connects the 1,290 and 1,335 days not only with the content of the vision of Daniel 11 (see v. 31) but also with the 2,300 evenings and mornings of Daniel 8:14 (see 8:13; 9:27). The very same apostate power that would establish the "abomination that causes desolation" in replacement to the "daily sacrifice" is described in Daniel 7 and 8 as the "little horn," and in Daniel 11 as the "king of the North." Therefore, the attempt to interpret some of the prophetic periods of Daniel (70 weeks, 2,300 evenings and mornings) as days that symbolize years and others (1,260 days, 1,335 days) as mere literal days is completely inconsistent with the prophetic-literary parallelism of the book of Daniel.
3. This theory rests on a non-biblical interpretation of the Hebrew term tamid ("daily," "continuous").
The theory that both the 1,290 days and the 1,335 days begin with the future Sunday law is based on the assumption that in Daniel 12:11 the expressions "daily sacrifice" and "abomination that causes desolation" mean Sabbath and Sunday respectively. But also this assumption lacks biblical foundation.
The expression "daily sacrifice" is the translation of the Hebrew term tamid, which means "daily" or "continuous," to which was added the word "sacrifice," which does not appear in the original text of Daniel 8:13 and 12:11. This term (tamid) is used in the Scriptures in regard not only to the daily sacrifice of the earthly sanctuary (see Exod 29:38, 42) but also to several other aspects of the continuous ministration of that sanctuary (see Exod 25:30; 27:20; 28:29, 38; 30:8; 1 Chr 16:6). In the book of Daniel the term refers obviously to the continuous priestly ministry of Christ in the heavenly sanctuary/temple (see Dan 8:9-14). The expression "abomination that causes desolation" implies the whole counterfeit system to that ministry, built upon the anti-biblical theories of the natural immortality of the soul, the mediation of the saints, the auricular confession, the sacrifice of the mass, etc.
We cannot agree with the theory that in Daniel 12 the "daily" represent simply the Sabbath and that the "abomination that causes desolation" represents only Sunday. To believe in this way we would need to empty those expressions from the broad meaning attributed to them by the biblical context in which they appear and by the overall consensus of the Scriptures.
4. This theory reflects the Jesuit futuristic interpretation of the Roman Catholic Counter-Reformation.
The defenders of the literal-futuristic interpretation of the 1,290 and 1,335 days pretend that their position is genuinely Adventist and plainly endorsed by the Spirit of Prophecy. But if we analyze the subject more carefully in the light of History we will perceive that this theory actually rejects the Historicism and the year-day principle of the Protestant tradition, aligning itself openly with the literalistic Futurism of the Roman Catholic Counter-Reformation.
The Protestant Reformers of sixteenth century identified the "little horn" as the Papacy, from which would originate the "abomination that causes desolation" mentioned by Daniel. With the intention of freeing the Papacy from such accusations, the Italian Cardinal Robert Bellarmine (1542-1621), the most able and renown of all Jesuit polemicists, suggested that the "little horn" was a mere king and that the 1,260 and 1,335 days were only literal days to be fulfilled only in the time-period just prior to the end of the world.  So contemporary Papacy could no longer be identified with the "little horn" or the "king of the North" and, consequently, could no longer be made responsible for the "abomination that causes desolation."
Many contemporary advocates of the futurist interpretation of the 1,290 and 1,335 days do not acknowledge the indebtedness of this theory to the Futurism of the Roman Catholic Counter-Reformation. But even so such individuals should at least recognize that "these futurist proposals rest essentially on a misunderstanding of the thought patterns of Hebrew prophecy," and that "they represent a reading of the Hebrew idiom through Western eyeglasses." 
5. This theory disregards the warnings of the Spirit of Prophecy against the attempt of extending the fulfillment of any time-prophecy beyond 1844.
If this theory would be correct then, as soon as the Sunday law would be promulgated, we would already know in advance when probation would end and when Christ's Second Coming would take place. This is, therefore, another subtle and tricky way of setting the time for the final events. As original and creative as these attempts might seem, they are nothing else than speculative proposals that ignore and/or despise, in the name of the Spirit of Prophecy, the proper warnings of the Spirit of Prophecy on this matter.
As early as 1850 Ellen White warned, "The Lord showed me that TIME had not been a test since 1844, and that time will never again be a test." Later on she added that "there will never again be a message for the people of God that will be based on time." "The Lord showed me that the message must go, and that it must not be hung on time; for time will never be a test again." "God has not revealed to us the time when this message will close, or when probation will have an end."  It will be only after the close of probation and shortly before the Second Coming that God will declare to the saints "the day and hour of Jesus' coming." 
Commenting the expression "there should be time no longer" (Rev 10:6, KJV), Ellen White stated in 1900 that "this time, which the angel declares with a solemn oath, is not the end of this world's history, neither of probationary time, but of prophetic time, which should precede the advent of our Lord. That is, the people will not have another message upon definite time. After this period of time, reaching from 1842 to 1844, there can be no definite tracing of the prophetic time."
Being this the case, why then some professed Adventists still continue to insist on reapplying the 1,290 days and the 1,335 days of Daniel 12 to the future? Only God can judge the degree of sincerity of such people. But one thing is certain, "Faith in a lie will not have a sanctifying influence upon the life or character. No error is truth, or can be made truth by repetition, or by faith in it. . . . I may be perfectly sincere in following a wrong road, but that will not make it the right road, or bring me to the place I wished to reach."
It is therefore evident that the theory of a future fulfillment of the 1,290 and 1,335 days (1) is based on a partial and biased reading of the Spirit of Prophecy; (2) breaks the prophetic-literary parallelism of the book of Daniel; (3) rests on a non-biblical interpretation of the Hebrew term tamid ("daily," "continuous"); (4) reflects the Jesuit futurist interpretation of the Roman Catholic Counter-Reformation; and (5) disregards the warnings of the Spirit of Prophecy against the attempt of extending the fulfillment of any time-prophecy beyond 1844.
In a time when the winds of false doctrines will be blowing with strong intensity (see Eph 4:14) "to deceive, if possible, even the elect" (Matt 24:24, NKJV), we will be secure only if we are grounded on the clear and unmovable Word of God. All "new lights," to be true, need to be in perfect harmony with the overall consensus of the Scriptures and of the inspired writings of Ellen White. The watchmen of God's people should never allow human conjectures and speculations to hinder them from giving the trumpet the right sound (see Ezek 33:1-9; 1 Cor 14:8).
 LeRoy Froom, The Prophetic Faith of Our Fathers (Washington, DC: Review and Herald, 1954), 4:205-6.
 W[illia]m Miller, Evidences from Scripture and History of the Second Coming of Christ about the Year A.D. 1843, and of His Personal Reign of 1000 Years (Brandon, [VT]: Vermont Telegraph Office, 1833), 31; idem, Evidence from Scripture and History of the Second Coming of Christ, about the Year 1843; Exhibited in a Course of Lectures (Boston: Joshua V. Himes, 1842), 95-104, 296-97; idem, "Synopsis of Miller's Views," Signs of the Times, Jan. 25, 1843, 148-49.
 See P. Gerard Damsteegt, Foundations of the Seventh-day Adventist Message and Mission (Grand Rapids, MI: Eerdmans, 1977), 168-70.
 See, for example, [Uriah Smith], "Synopsis of the Present Truth. No.12," Advent Review, and Sabbath Herald, Jan. 28, 1858, 92-93; Stephen N. Haskell, The Story of Daniel the Prophet (Berrien Springs, MI: Advocate Publishing Company, 1903), 263-65; J. N. Loughborough, "The Thirteen Hundred and Thirty-Five Days," Advent Review, and Sabbath Herald, Apr. 4, 1907, 9-10; Uriah Smith, The Prophecies of Daniel and the Revelation, rev. ed. (Washington, DC: Review and Herald, 1944), 330-31; George M. Price, The Greatest of the Prophets: A New Commentary on the Book of Daniel (Mountain View, CA: Pacific Press, 1955), 337-42; Araceli S. Melo, Testemunhos Históricos das Profecias de Daniel (Rio de Janeiro, Brazil: [Laemmert], 1968), 727- 29; Francis D. Nichol, ed., The Seventh-day Adventist Bible Commentary, rev. ed. (Washington, DC: Review and Herald, 1977), 4, 880-81; Vilmar E. González, "Os 1290 e 1335 dias em Daniel 12," Revista Adventista (Brazil), Sept. 1982, 43-45; Jacques B. Doukhan, Daniel: The Vision of the End, rev. ed. (Berrien Springs, MI: Andrews University Press, 1989), 153; William H. Shea, "Time Prophecies of Daniel 12 and Revelation 12-13," in Frank B. Holbrook, ed., Symposium on Revelation -Book I, Daniel and Revelation Committee Series, vol. 6 (Silver Spring, MD: Biblical Research Institute of the General Conference of Seventh-day Adventists, 1992), 327-60; William H. Shea, Daniel 7-12: Prophecies of the End Time, The Abundant Life Bible Amplifier (Boise, ID: Pacific Press, 1996), 217-23; Reinaldo W. Siqueira, "Daniel 12: Interpretação a Partir do Contexto do Livro," Parousia (Brazil) 1, no.2 (2nd Semester 2000): 61-66.
 A helpful critical analysis of several more recent theories about the fulfillment of the 1260, 1290, and 1335 days is provided in Victor Michaelson, Delayed Time-Setting Heresies Exposed (Payson, AZ: Leaves-Of-Autumn, 1989).
 E. G. White, "To the Church in Bro. Hastings house," Nov. 7, 1850 (Letter H-28, 1850). Published in idem, Manuscript Releases (Silver Spring, MD: Ellen G. White Estate, 1990), 5:203; ibid., 6:251; ibid., 16:208.
 J[ames W[hite], "The Judgment," Advent Review, and Sabbath Herald, Jan. 29, 1857, 100.
 See, for example, J. N. Loughborough, "The Hour of His Judgment Come," Advent Review, and Sabbath Herald, Feb. 14, 1854, 30; U[riah] S[mith], "Short Interviews with Correspondents," Advent Review, and Sabbath Herald, Feb. 24, 1863, 100; [idem], "The Sanctuary ," Advent Review, and Sabbath Herald, Sept. 8, 1863, 116.
 E. G. White, "'It Is Not for You to Know the Times and the Seasons,'" Advent Review, and Sabbath Herald, Mar. 22, 1892, 177-78; republished in idem, in Seventh-day Adventist Bible Commentary, 6: 1052; idem, Selected Messages (Washington, DC: Review and Herald, 1958), 1:188.
 [ldem], "Temperance," Ms 50, 1893 (published in idem, Sermons and Talks [Silver Spring, MD: E. G. White Estate, 1990], 1:225-26); idem, to "Dr. J. H. Kellogg," Letter K-59, Nov. 22, 1896 (published in idem, Testimonies to Ministers and Gospel Workers [Mountain View, CA: Pacific Press, 1923], 115); idem, "Diary ," Ms 176, Nov. 4, 1899 (published in Seventh-day Adventist Bible Commentary, 4:1174); idem, "Help to Be Given to Our Schools," Ms 10, 1900 (published in Seventh-day Adventist Bible Commentary, 7:949); idem, "To Our Church Members in Australasia," Letter 8-6, Jan. 17, 1907 (published in [Australasian] Union Conference Record, Mar. 11, 1907, 1-2).
 Damsteegt, 169.
 Shea, Daniel 7-12, 217-18.
 See Froom, 2:241-463, passim.
 See ibid., 495-502.
 [Frank B. Holbrook], "Editorial Synopsis" to W. H. Shea's article, "Time Prophecies of Daniel 12 and Revelation 12-13," in Holbrook, ed., Symposium on Revelation - Book I, 327.
 E. G. White, "Dear Brethren and Sisters," Present Truth, Nov. 1850, 87.See also idem, Early Writings (Washington, DC: Review and Herald, 1945), 75.
 Idem, Selected Messages, 1:188, 191.
 ldem, The Great Controversy between Christ and Satan (Washington, DC: Review and Herald, 1911 ), 640. See also idem, Early Writings, 15, 296-97.
 Ellen G. White's commentaries in Seventh-day Adventist Bible Commentary, 7:971.
 Idem, Selected Messages, 2:56.
 See idem, Counsels to Writers and Editors (Nashville, TN: Southern Publishing Association, 1946), 33-51.