I just checked the Amorphophallus titanum plant, and the spathe had completely pulled away from the spadix in the two hours since I last looked at it. Tonight will be the night! I would expect it to be fully open by 8:00-10:00, and at the peak of fragrance around 12:00. By tomorrow morning it will be partially closed up, and not nearly as smelly.
The greenhouse will be open until late (1:00 AM), and then open again bright and early tomorrow at our usual time.