Jeremiah 39:1

39:1 King Nebuchadnezzar of Babylon came against Jerusalem with his whole army and laid siege to it. The siege began in the tenth month of the ninth year that Zedekiah ruled over Judah. 1 

Jeremiah 52:12

52:12 On the tenth 2  day of the fifth month, 3  in the nineteenth year of King Nebuchadnezzar of Babylon, Nebuzaradan, the captain of the royal guard 4  who served 5  the king of Babylon, arrived in Jerusalem.

1 sn 2 Kgs 25:1 and Jer 52:4 give the more precise date of the tenth day of the tenth month of the ninth year which would have been Jan 15, 588 b.c. The reckoning is based on the calendar that begins the year in the spring (Nisan = March/April).

2 tn The parallel account in 2 Kgs 25:8 has “seventh.”

3 sn The tenth day of the month would have been August 17, 586 b.c. in modern reckoning.

4 tn For the meaning of this phrase see BDB 371 s.v. טַבָּח 2 and compare the usage in Gen 39:1.

5 tn Heb “stood before.”