Background decoding, when enabled, will automatically decode anything that is available, that means: anything that is registered in the bandplan, is enabled, and is available on a currently running profile.

 

I suppose your device is decoding on profiles that are being used by clients, or you have the "keep device running at all time" option checked, in which case it will just continue decoding on the last profile used on the device. The schedule is a feature that will take control of the device if no clients are using the device any more, it just gives you more control over what the device should do while idle.

 

PSKreporter on the other hand has its own configuration, where it can be en- or disabled separately.