Interpretation. The Seventh-day Adventist reckoning of the 2300 days of Dan. 8:14 as 2300 years was inherited directly from the Millerite movement and indirectly from earlier writers of the historical school of prophetic interpretation, which is characterised by the use of the year-day principle. Other schools of interpretation have seen this time period as 2300 literal "evenings and mornings" of desecration of a literal Jewish temple, either by Antiochus in the past or by a personal antichrist in the future.
Many historicist writers on the prophecies in various countries had anticipated William Miller in reckoning the 2300 days as years, beginning at the starting point of the 70 weeks. A number of them had arrived at approximately Miller's dating.
1. Chronology, From Petri to Miller. As early as 1768 Johann Petri, a Reformed pastor near Frankfurt, Germany, wrote that the 2300 days, or years, and the 70 weeks (490 years) were to be computed as beginning together. He reckoned the 2300 from 453 years before Christ's birth to 1,847 years after it, and placed the Crucifixion in the middle of the seventieth week (Dan. 9:27) and the Second Advent at the end of the 2300 days, leading to the millennium. A half century later and onward, many expositors dated the period in similar fashion, either 457 B.C. to A.D. 1843 or 1844, or 453 B.C. to A.D. 1847; others used different dates, some ending in 1866 or 1867. The figure 1847 was in many instances (for example, for Petri) virtually equivalent to 1843 because it was reckoned as 1,847 years from the birth of Christ, which was dated in 4 B.C. by the then-popular Ussher's chronology.
In his Prophetic Faith of Our Fathers, volume 4, L. E. Froom lists about 35 writers between 1810 and 1844 who ended the period in 1843 or 1844, most of them in England, but including some in Scotland, Ireland, Germany, and the United States; about 25 who looked to 1847 (five of them using a supposed 2400-year period), writing in England, Germany, India, Canada, the United States, and Mexico. Not all of these began the 70 weeks and the 2300 years together, and a number of those who ended the 2300 years in the 1840s calculated other prophetic periods, such as the 1290 and 1335 years, beyond the 2300 years to such dates as 1877 and 1922. However, for the 2300 years, there was a great vogue for computing the period as ending in the 1840s, and most writers arrived at that dating by computing from the 70 weeks as ending in the time of Christ.
William Miller arrived at his expectation of the Second Advent in 1843 mainly on his computation of the 2300 years. He simply accepted, without question, A.D. 33 (the Crucifixion date as printed in the margin of his KJV Bible) as the end of the 70 weeks, which he took to be the first 490 years of the 2300-year period. Then, he reasoned, the rest of the longer period would extend 1810 years beyond that (2300 â€” 490 = 1810), and A.D. 33 + 1810 = 1843. Similarly, to count backward from A.D. 33 as the end of the 70 weeks, he calculated that this period of 490 years began in 457 B.C. (he merely subtracted: 490 â€” 33 = 457). Further, he found the figure "457 B.C." in the margin of Ezra 7 as the date for the return of Ezra to Jerusalem under the decree of Artaxerxes' seventh year, to restore the commonwealth of Judah under Jewish law. This decree Miller equated with "the commandment to restore and to build Jerusalem" (Dan. 9:25), from which the 70 weeks were to begin. Further, he could see that 457 years before Christ plus 1843 years after Christ totals 2300 years.
These two dates (457 B.C. and A.D. 33) in English Bible margins, derived from Archbishop Ussher's chronology and generally accepted as authoritative by theologians of that day, seemed to Miller, as to others before him, to make the computation obvious and inescapable.
Miller's equation 457 + 1843 = 2300, like Petri's similar equation 453 + 1847 = 2300, ignored a one-year difference in computing from B.C. to A.D. dates. This error was to be corrected later by some of Miller's colleagues (see sec. 3 below).
2. Events at End of 2300 Years. There was relatively little argument about the beginning date, the decree of the seventh year of Artaxerxes, but there was a variety of expectations among expositors in regard to the cleansing of the sanctuary that was to take place at the end of the 2300 years. This event had been interpreted variously by Miller's predecessors as the purification of the church, the liberation of Palestine from the Muslims, the end of the Papacy or of Islam, the beginning of the millennium, the restoration of true worship, or, in some cases, the return of Christ to set up a kingdom on earth. (Petri, for example, expected the end of the abomination in the church, and the coming of Christ to set up His kingdom and begin the millennium.) Miller held that the cleansing of the sanctuary was the purification of the temple of lively stones-the people of Godâ€”through the first resurrection at the Second Advent; later he included the cleansing of Palestine (the place of God's sanctuary) and of the whole earth in the final fires. This fiery cleansing, he held, would destroy the last trace of sin and purify the earth for the introduction of the divine kingdom, which would last not merely 1,000 years, but throughout eternity.
The Millerite view differed from all the rest in equating the end of the 2300 days with the end of probation, the end of this world and its mortal, sinful inhabitants, and the ushering in of the eternal kingdom of the glorified saints on the renewed earth.
3. Millerite Revision From 1843 to 1844. Miller came to define his "about 1843" as the "Jewish year 1843," which he thought extended from equinox to equinox, Mar. 21, 1843, to Mar. 21, 1844. However, beginning in 1843, some of his colleagues, especially Hale, Bliss, Litch, and others, began to reckon the "Jewish year 1843" by the Jewish lunar calendar. They ended it (according to the reckoning formerly used by the Karaite Jews) a month later than the modern Jewish calendar with the new moon of April 1844. An editorial, presumably by S. Bliss (in The Signs of the Times 5:123, June 21, 1843), discusses this, and also introduces the idea that Miller's 1843 is only the 2300th year (and A.D. 33 the 490th year) from 457 B.C., and that the 70 weeks and the 2300 years actually ended in 34 and 1844, respectively. But it was not until later that it was explained why the computation by straight subtraction (2300 â€” 457 = 1843) was a year off.
By the spring of 1843 several articles in Millerite journals pointed out that 2300 full years beginning at any time in 457 B.C. would extend to the same point in A.D. 1844, not in 1843. The explanation was that 2300 years would require 457 complete B.C. years plus 1843 complete A.D. years, which if counted from the beginning of 457 B.C. would continue to the end of A.D. 1843; therefore, if the period began at any point of time after the beginning of 457, it would not end until that same point of time after the end of 1843, that is, in 1844.
(The reason for this is that in historical dating, the year immediately preceding A.D. 1 is called the year 1 B.C., for there is no zero year between.)
But already in February 1844 Samuel S. Snow wrote an article using this reckoning of 2300 full years from 457 B.C. (from the autumn, according to his view). Therefore he reached the conclusion that the Second Advent was not to be looked for until the autumn of 1844, and that the sixty-ninth week ended in the autumn of A.D. 27 (Midnight Cry 6:243, 244, Feb. 22, 1844). Little attention was given to this new expectation until the summer, by which time he had expanded his explanation and arrived at a definite date, Oct. 22.
4. Revision of Seventy Weeks. Miller had ended the 70 weeks with the Crucifixion in A.D. 33, but already by 1843 there was discussion of the idea that the cross was in the "midst" of the seventieth week, and authors were cited for A.D. 31 as the Crucifixion date (see Bliss, in Signs of the Times 6:132-136, Dec. 5, 1843).
Now in early 1844 the correction of the subtraction error led not only to the ending of the 2300 days in 1844 instead of 1843 but also to the adopting of several new positions on the 70 weeks:
(1) that the 70 weeks, or 490 years, ended in A.D. 34, not 33;
(2) that the Crucifixion took place, not at the end, but in the midst (Dan. 9:27) of the seventieth week, three and a half years before the endâ€”that is, in A.D. 31 (the date being based on William Hales' New Analysis of Chronology), and that the anointing of Christ (at His baptism) at the end of the sixty-ninth week would leave three and a half years for His ministry before the "midst" of the week;
(3) that the seventieth week, ending three and a half years later than the Crucifixion, which occurred in the spring (at Passover time), would therefore have ended in the autumn of A.D. 34;
(4) that consequently the principal points of the seventieth week could be lined up at specific times: autumn 27 (Christ's baptism), spring 31 (the Crucifixion after a three-and-a-half-year ministry), and autumn 34 (the end of the seven years allotted "to confirm the covenant" by Christ and, after Him, by the apostles).
This lent conviction to the final conclusion that the concurrently beginning 2300 years would also end at a specific timeâ€”the autumn of 1844. Thus, even after Miller's year of 1843/44 ran out in the spring, the end was still to be looked for.
This autumn ending point came to be assigned to the tenth day of the seventh Jewish month as the proper day for the antitypical cleansing of the sanctuary, and the date was calculated to Oct. 22, fixed according to the former Karaite calendar. The preaching of this date resulted in the "seventh-month movement," which culminated in the expectation of the return of Christ on that day, and in the Great Disappointment. But Miller never set this specific date, and he accepted it only a few weeks before it arrived.
5. Seventh-day Adventist Interpretation of the Expected Fulfilment. With the passing of Oct. 22, most of the Adventists concluded that their chronology was in error, and during the next few years progressively later dates for the end of the 2300 days were advanced by one group or another. But a sizeable minority held that the error was not in the reckoning of the period but in the interpretation of the closing event to be expected. Among these were a still smaller minority, the little groups who came to form the nucleus of the later Seventh-day Adventist organisation. Retaining the Millerite chronology of the 2300 years as revised in 1844, that is, as reckoned from autumn 457 B.C. to autumn 1844, they explained the cleansing of the sanctuary, in terms of the antitypical day of atonement, as representing the final phase in Christ's priestly work "in the heavens" as "minister of the sanctuary, and of the true tabernacle" (Heb. 8:1, 2), which phase they came to define as an "investigative judgement." -- Seventh-day Adventist Encyclopaedia.