Jamieson, Fausset and Brown on Jeremiah 36:6

6. go--on the following year (Jr 36:9).

fasting day--(See Jr 36:9). An extraordinary fast, in the ninth month (whereas the fast on the great day of atonement was on the tenth day of the seventh month, Le 16:29; 23:27-32), appointed to avert the impending calamity, when it was feared Nebuchadnezzar, having in the year before (that is, the fourth of Jehoiakim), smitten Pharaoh-necho at Carchemish, would attack Judea, as the ally of Egypt (2Ki 23:34, 35). The fast was likely to be an occasion on which Jeremiah would find the Jews more softened, as well as a larger number of them met together.