HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\QuietHours

Turn off calls during Quiet Hours
- HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\QuietHours\AllowCalls
Set the time Quiet Hours ends each day
- HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\QuietHours\ExitTime
Set the time Quiet Hours begins each day
- HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\QuietHours\EntryTime
Turn off Quiet Hours
- HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\QuietHours\Enable