Missing years (Jewish calendar)

The missing years in the Hebrew calendar refer to a chronological discrepancy between the rabbinic dating for the destruction of the First Temple in 422 BCE (3338 Anno Mundi) and the academic dating of it in 587 BCE. In a larger sense, it also refers to the discrepancy between conventional chronology versus that of Seder Olam in what concerns the Persian period during which time it exercised hegemony over Israel, a period which spanned 207 years according to conventional chronology, but only 34 years according to Seder Olam. Invariably, the resulting timeframe also affects the number of years the Second Temple stood, said by a late rabbinic tradition to have stood 420 years, but by conventional chronology 589 years.

Dating in academic sources
The academic datings in question are confirmed by a variety of Persian, Babylonian and Greek sources, which include records of datable astronomical observations such as eclipses, although there are disagreements among modern scholars, ranging from 1 to 2 years, over some of the dates in the conventional chronology.

Siege of Jerusalem (597 BC)
Both the Babylonian Chronicles and the Bible indicate that Nebuchadnezzar captured Jerusalem. The Babylonian Chronicles (as published by Donald Wiseman in 1956) establish that Nebuchadnezzar captured Jerusalem the first time on 2 Adar (16 March) 597 BCE. Before Wiseman's publication, E. R. Thiele had determined from the biblical texts that Nebuchadnezzar's initial capture of Jerusalem occurred in the spring of 597 BCE, while other scholars, including William F. Albright, more frequently dated the event to 598 BCE.

Second siege and destruction of the First Temple
According to the Bible, Nebuchadnezzar installed Zedekiah as king after his first siege, and Zedekiah ruled for 11 years before the second siege resulted in the end of his kingdom.

Although there is no dispute that Jerusalem fell the second time in the summer month of Tammuz, Albright dates the end of Zedekiah's reign (and the fall of Jerusalem) to 587 BCE, whereas Thiele offers 586 BCE. Thiele's reckoning is based on the presentation of Zedekiah's reign on an accession basis, which was used for most but not all of the kings of Judah. In that case, the year that Zedekiah came to the throne would be his first partial year; his first full year would be 597/596 BCE, and his eleventh year, the year Jerusalem fell, would be 587/586 BCE. Since Judah's regnal years were counted from Tishrei in autumn, this would place the end of his reign and the capture of Jerusalem in the summer of 586 BCE.

Dating in traditional Jewish sources
A variety of rabbinic sources state that the Second Temple stood for 420 years. In traditional Jewish calculations, based on Seder Olam Rabbah, the destruction of the Second Temple fell in the year 68 of the Common Era, implying that it was built in about 352 BCE. Adding 70 years between the destruction of the First Temple and the construction of the Second Temple, it follows that the First Temple was destroyed in around 422 BCE. While acceptance of this chronology was widespread among ancient rabbis, it was not universal: Pirkei deRabbi Eliezer, Midrash Lekach Tov, and numerous rishonim disagree with the chronology of Seder Olam Rabbah.

The traditional Jewish date recognized by the rabbis as the "year of destruction" is approximately 165 years later than the accepted year of 587 or 586 BCE. This discrepancy is referred to as the "missing years".

Details of rabbinic chronology
According to the Talmud and Seder Olam Rabbah, the Second Temple stood for 420 years, with the years divided up as follows:
 * 103 years (35 BCE – 68 CE) = Herod's Dynasty.
 * 103 years (138–35 BCE) = Hasmonean Dynasty.
 * 180 years (318–138 BCE) = Grecian rule over Israel
 * 34 years (352–318 BCE) = Persian rule while the Second Temple stood (not including additional years of Persian rule before the Temple's construction).

The date of 318 BCE for the Greek conquest of Persia is evident from the Talmud, which implies that that Greek rule began six years before the beginning of the Seleucid era (which occurred in 312/11 BCE). (Note that in academic chronology, Alexander conquered the Persian empire between 334–330 BCE.)

Seventy years passed between the destruction of the First Temple and the building of the Second Temple in the seventy first year, so construction of the Second Temple in 352 BCE implies that the First Temple was destroyed in 423 BCE.

Similarly, Megillat Antiochus implies that the Second Temple was built in 352 BCE, and thus that the First Temple was destroyed in 423 BCE.

The figure of 420 years is likely derived from the prophecy of seventy weeks in. The rabbis interpreted this passage as referring to a period of 490 years which would pass between the destructions of the First and Second Temple—70 years between the Temples, plus 420 years of the Second Temple, starting in the 71st year after the destruction, though the passage can plausibly be interpreted in other ways.

Proposed explanations
If traditional dates are assumed to be based on the standard Hebrew calendar, then the differing traditional and modern academic dating of events cannot both be correct. Attempts to reconcile the two systems must show one or both to have errors.

Missing years in Jewish tradition
Scholars see the discrepancy between the traditional and academic date of the destruction of the First Temple arising as a result of Jewish sages miscounting the reign lengths of several Persian kings during the Persian Empire's rule over Israel. Modern scholars tally 14 Persian kings whose combined reigns total 207 years. By contrast, ancient Jewish sages only mention four Persian kings totaling 52 years. The reigns of several Persian kings appear to be missing from the traditional calculations.

Certain verses in the Bible itself suggest a longer Persian era, such as where six generations of priests are listed in the Persian period. However, as the Bible does not mention any significant events occurring in those additional years, the later rabbis may have consciously chosen to omit the years from their chronology.

Azariah dei Rossi was likely the first Jewish authority to claim that the traditional Hebrew dating is not historically precise regarding the years before the Second Temple,   and suggests that the Sages of Israel may have chosen to include in their chronology only those years of the period of Persian dominion that were clearly expressed or implied in the Bible. Additional time, the length of which was not clearly stated, was chosen to be ignored. Nachman Krochmal agreed with dei Rossi, pointing to the Greek name Antigonos mentioned in Pirkei Avot 1:3 as proof that there must have been a longer period to account for this sign of Hellenic influence. Dei Rossi and Krochmal argued that when the length of a historical period was unknown, Seder Olam Rabbah took the method of assuming the shortest possible length.

Astrologer and chronicler, Raḥamim Sar-Shalom, following the view of dei Rossi, suggests that the purpose of the author of Seder Olam was only to state the number of years of the Persian period that were included in the Bible, and that a lack of understanding of the purpose by the Amoraim is what caused them, among other things, to calculate the date from creation erroneously. The "missing years" not only offset the span of the Persian period, but also offset the number of years collected since the first man, Adam, walked the face of the earth.

Solomon Judah Loeb Rapoport noted that the traditional Jewish chronology, when combined with another rabbinic tradition, places the Exodus from Egypt at exactly 1000 years prior to the Seleucid era (known in Jewish sources as "Minyan Shtarot"). He suggests that the authors of the traditional Jewish chronology intentionally omitted years from the Persian period to obtain the round number with the intent of allowing Jews who had counted years from the Exodus to easily switch to the Seleucid era system, used by Greek rulers at the time.

David Zvi Hoffmann points out that the Mishnah in Avot (1:4) in describing the chain of tradition uses the plural "accepted from them" even though the previous Mishnah mentions only one person. He posits that there must have been another Mishnah mentioning two sages that was later removed.

Shimon Schwab interpreted the Biblical words "seal the words and close the book" as a commandment to obscure the Biblical chronology so that it would not be possible to accurately calculate the time of the Messiah's arrival. Thus, according to Schwab, the traditional Jewish calendar intentionally omitted years from the Persian period. However, Schwab later withdrew that suggestion for numerous reasons.

A 2006 article in Ḥakirah journal suggested that the sages were concerned with the acceptance of the Mishnah. There existed a rabbinical tradition that the year 4000 marked the close of the "era of Torah". Thus, it is proposed, the sages arranged the chronology so that the redaction of the Mishnah should coincide with that date and thus have a better chance of acceptance.

Mordechai Breuer suggested that like other works of midrash, the tradition chronology in Seder Olam Rabbah was never meant to be taken literally but rather was intended to be symbolic.

Some Jewish thinkers, including Isaac Abarbanel, Chaim Hirschensohn and Adin Steinsaltz, have argued that the original Jewish chronology agreed with the academic chronology, but later misunderstandings or textual corruptions of Seder Olam Rabbah gave the impression that it refers to a shorter period of time. However, Seder Olam Rabbah's chronology is implicit in many different passages, and it is difficult to plausibly explain all of the passages in a way that agrees with the academic chronology.

Critiques of academic dating
Attempts have been made to reinterpret the historical evidence to agree with the rabbinic tradition. These advocates will sometimes accuse historians of overly trusting the historian Herodotus, although the standard dating is based on many things including archaeology and other historians. Mainstream scholarship has rejected these attempts.

Other advocates of alternative chronology will sometimes invoke the rabbinic tradition. David Rohl's New Chronology redates much of Egyptian history and he claims that his chronology matches the events of Exodus and other parts of the Bible better, as an example.