Another date that can be used as a pivotal point is the year 539 B.C.E., supported by various historical sources as the year for the overthrow of Babylon by Cyrus the Persian. (Secular sources for Cyrus’ reign include Diodorus, Africanus, Eusebius, and Ptolemy, as well as the Babylonian tablets.) During Cyrus’ first year his decree releasing the Jews from exile was given. And, as considered in the article on CYRUS, it is very probable that the decree was made by the winter of 538 B.C.E. or toward the spring of 537 B.C.E. This would permit the Jews time to make necessary preparations, effect the four-month journey to Jerusalem, and still arrive there by the seventh month (Tishri, or about October 1) of 537 B.C.E.​—Ezr 1:1-11; 2:64-70; 3:1.

Jerusalem came under final siege in Zedekiah’s 9th year (609 B.C.E.), and the city fell in his 11th year (607 B.C.E.), corresponding to Nebuchadnezzar’s 19th year of actual rule (counting from his accession year in 625 B.C.E.). (2Ki 25:1-8) In the fifth month of that year (the month of Ab, corresponding to parts of July and August) the city was set afire, the walls were pulled down, and the majority of the people were led off into exile. However, “some of the lowly people of the land” were allowed to remain, and these did so until the assassination of Gedaliah, Nebuchadnezzar’s appointee, whereupon they fled into Egypt, finally leaving Judah completely desolate. (2Ki 25:9-12, 22-26) This was in the seventh month, Ethanim (or Tishri, corresponding to parts of September and October). Hence the count of the 70 years of desolation must have begun about October 1, 607 B.C.E., ending in 537 B.C.E. By the seventh month of this latter year the first repatriated Jews arrived back in Judah, 70 years from the start of the full desolation of the land.​—2Ch 36:21-23; Ezr 3:1.