Here it says the seventh of the month. In Yirmeyah (52:12) it says the 10th!
Radak and Malbim, from Ta'anis 29a: On the seventh, Nochrim entered the Heichal. They ate, drank and acted lowly on the seventh and eighth, and on the ninth, close to dark, they set it on fire. It burned until the end of the 10th.
Malbim: Yirmeyah 52:12-13 says that on the 10th, Nevuzaradan came in front of Melech Bavel, and he commanded to burn everything.
Here and in Yirmeyah (52:12) it says that it was Nebuchadnetzar's 19th year. In Yirmeyah (52:29) it says the 18th!
Radak (from Ta'anis 29a): It was the end of his 18th year and the beginning of his 19th. This is like I explained above (24:12), the end of his seventh year and the beginning of his eighth.
Radak citing Megilah 11b: It was the 19th year of Nebuchadnetzar's reign, and the 18th year from when Yehoyachin was conquered.
