As weird as it looks, 12:00 PM is noon and 12:00 AM is midnight, so fortunately, there's no bug. [:)]
As for the 12/24 hour preferences option, I didn't forget it but I don't add new words in the user interface of the program in maintenance versions to avoid updating the 16 available translations of Sweet Home 3D. To be sincere, I would also prefer to avoid such an option. As I can detect easily the user country, I think I'll simply use the 12-hour notation only for the countries who use it.