Here "in the days of" is an idiom that refers to the time when a king reigned. Alternate translation: "when Johoiakim son of Josiah was king of Judah" (See: [[rc://en/ta/man/translate/figs-idiom]])
This is the fifth month of the Hebrew calendar. It is during the last part of July and the first part of August on Western calendars. (See: [[rc://en/ta/man/translate/translate-hebrewmonths]] and [[rc://en/ta/man/translate/translate-ordinal]])
This refers to the rule of Zedekiah. This can be stated explicitly. Alternate translation: "of the reign of Zedekiah" (See: [[rc://en/ta/man/translate/figs-explicit]])
This can be stated in active form. It can be stated clearly that they were taken to Babylon. Alternate translation: "when the army of Babylon took the people of Jerusalem away as prisoners" or "when the army of Babylon took the people of Jerusalem as prisoners to Babylon" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/figs-explicit]])