If you aren't using Zoneswitch now for other reasons, you could try the MC "Scheduler" function (left Navigation Bar > Services & Plug-ins > Scheduler) and the MCC Command /MCC 10011 to switch Zone at 10pm, and then switch it back for the following day.
I suspect MC will have to be running for the Task to execute. Maybe it would work with just Media Server running. Test. MC will wake a PC to run its tasks I think. Test.
Note that this may change the Zone even while you are watching something, which could have undesirable results. If a video is playing when the task runs, I'm pretty sure it won't change playback for the current video.
It would be better if there was an MCC Command to turn on and off Adaptive Volume, but there doesn't seem to be one. There may be an MCWS command. Check... Ah yes, there is. i.e.
http://localhost:52199/MCWS/v1/DSP/SetAdaptiveVolume?Strength=2But that seems to be an old version of Adaptive Volume, using a strength setting. However, that did set Night Mode on my PC.
http://localhost:52199/MCWS/v1/DSP/SetAdaptiveVolume?Strength=0Turned Adaptive Volume off.
You can run MCWS command from the MC Scheduler I believe. Investigate.
An alternative would be just to apply a DSP Preset that included Adaptive Volume. I can't see a command to do that. Investigate.
Wait...MCWS
http://localhost:52199/MCWS/v1/Playback/LoadDSPPreset?Zone=-1&ZoneType=ID