Here it says the 10th of the month. In Melachim II, 25:8 it says the seventh!
Radak and Malbim (both in Melachim II, 25:8, 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 (Melachim II, 25:8): Here it says that on the 10th, Nevuzaradan came in front of Melech Bavel, and he commanded to burn everything.
Here and in Melachim II, 25:8 it says that it was Nebuchadnetzar's 19th year. Verse 29 says the 18th!
Radak (Melachim II, 25:8 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 (Melachim II, 25:8, citing Megilah 11b): It was the 19th year of Nebuchadnetzar's reign, and the 18th year from when Yehoyachin was conquered.
