Isaiah, 8-9 in the Bible Encyclopedia - ISBE

8. Isaiah's Prophecies Chronologically Arranged: The editorial arrangement of Isaiah's prophecies is very suggestive. In the main they stand in chronological order. That is to say, all the dates mentioned are in strict historical sequence; e.g. Isa 6:1, "In the year that king Uzziah died" (740 BC); 7:1, "In the days of Ahaz" (736 ff BC); 14:28, "In the year that king Ahaz died" (727 BC); 20:1, "In the year that Tartan came unto Ashdod, when Sargon the king of Assyria sent him" (711 BC); 36:1, "In the 14th year of king Hezekiah" (701 BC). These points are all in strict chronological order. Taken in groups, also, Isaiah's great individual messages are likewise arranged in true historical sequence; thus, Isa 1 through 6 for the most part belong to the last years of Jotham's reign (740-736 BC); Isa 7 through 12 to the period of the Syro-Ephraimitic war (734 BC); Isa 20, to the year of Sargon's siege of Ashdod (711 BC); Isa 28 through 32, to the invasion of Judah by Sennacherib (701 BC); while the distinctively promissory portions (Isa 40 through 66), as is natural, conclude the collection. In several minor instances, however, there are notable departures from a rigid chronological order. For example, Isa 6, which describes the prophet's initial call to preach, follows the rebukes and denunciations of Isa 1 through 5; but this is probably due to its being used by the prophet as an apologetic. Again, the oracles against foreign nations in Isa 13 through 23 belong to various dates, being grouped together, in part, at least, because of their subject-matter. Likewise, Isa 38 through 39, which give an account of Hezekiah's sickness and Merodach-baladan's embassy to him upon his recovery (714-712 BC), chronologically precede Isa 36 through 37, which describe Sennacherib's investment of Jerusalem (701 BC). This chiastic order, however, in the last instance, is due probably to the desire to make Isa 36 through 37 (about Sennacherib, king of Assyria) an appropriate conclusion to Isa 1 through 35 (which say much about Assyria), and, on the other hand, to make Isa 38 through 39 (about Merodach- baladan of Babylon) a suitable introduction to Isa 40 through 66 (which speak of Babylon)...

Link: https://bible-history.com/isbe/I/ISAIAH,+8-9/