“the fifth year of king Jehoiachin’s captivity.” Ezekiel is the most exactly dated of all the prophetic books, and the dates reckoned from the captivity of king Jehoiachin of Judah (2 Kings 24:8-17; 2 Chron. 36:9-10). There are 15 dated visions in Ezekiel, and many undated revelations, for example, Ezekiel 12 has five undated revelations from Yahweh (cp. Ezek. 12:1, 8, 17, 21, 26).
Ezekiel 1:1-2 is the first dated vision, and it occurred in the fifth year of Jehoiachin’s captivity, fourth month, fifth day, which scholars have pinpointed as July 31, 593 BC.
Ezekiel was taken captive by Nebuchadnezzar in the second major wave of the deportations of the Israelites to Babylon. The first had come in the “first year” of Nebuchadnezzar (which in Babylonian biblical counting was his accession year, but in non-accession counting was his first actual year). This was the 3rd year of Jehoiakim according to Babylonian counting (Dan. 1:1) and the fourth year of Jehoiakim according to Judean dating (Jer. 25:1; cp. Jer. 46:2). Daniel had been taken captive to Babylon in the accession year of Nebuchadnezzar, which was nine years before Ezekiel was carried to Babylon. Jeremiah was prophesying at the same time as Ezekiel and Daniel, but remained in Judah, eventually going to Egypt (Jer. 43:6-7).