Heidegger's Bible Handbook: Amos: Chronology

3. The time of the Prophet elicited from Amos 1:1. When did the earthquake happen? By that as a sign the Prophecy was confirmed.

Amos saw his words concerning Israelבִּימֵ֣י׀ עֻזִּיָּ֣ה מֶֽלֶךְ־יְהוּדָ֗ה וּבִימֵ֞י יָרָבְעָ֤ם בֶּן־יוֹאָשׁ֙ מֶ֣לֶךְ יִשְׂרָאֵ֔ל שְׁנָתַ֖יִם לִפְנֵ֥י הָרָֽעַשׁ׃, in the days of Uzziah king of Judah, and in the days of Jeroboam the son of Joash king of Israel, two years before the earthquake, Amos 1:1. Therefore, he entered the public arena with Uzziah and Jeroboam II reigning. Uzziah, who was also called Azariah, the ninth King after the division, began to reign in the twenty-seventh year of Jeroboam II, which Jeroboam was the great-grandson of Jehu, of the fourth house of the Kings of Israel, in order, with Zimri included, the thirteenth King of Israel, and began to reign in the fifteenth year of Amaziah,[1] and so in the one hundred and fifty-second year after the schism. And so Uzziah began in the one hundred and seventy-ninth year, and the Kingdoms of Jeroboam and Uzziah overlapped for fourteen years. Since Jeroboam reigned for forty-one years. Now, Amos began to prophesy in the days of Uzziah and of Jeroboam, two years before the earthquake: that the earthquake happened at that time, when Uzziah, on account of his invasion of sacerdotal offices, was smitten with leprosy,[2] is approved by Josephus, Antiquities, book IX, section 11, and following him the Hebrews, and Jerome also imitating them. Which certainly agrees little with an account of the times. Seeing that Uzziah reigned for fifty-two years.[3] But if it was the last of Jeroboam, when Amos began to prophesy (which still is hardly probable), Uzziah was already smitten with leprosy in the sixteenth year of his Kingdom, and was removed from the administration of affairs for thirty-six years. But Jotham, when he was made King, was twenty-five years old. But he, with his father removed, was in charge of affairs, as the elder of the house, which was not able to be done at such a time before he was born. And so there is no certainty in this Hebrew tradition. Therefore, since concerning the definite time of this earthquake nothing is certain, it is likely that a circumstance of the time time is not here noted, but rather a sign, which God willed to add to the sermons of Amos, whereby the Israelites might be roused to attention.

[1] 2 Kings 14:23. [2] See 2 Chronicles 26:16-23. [3] 2 Kings 15:2; 2 Chronicles 26:3.