With ColorOS 7 Oppo offers the possibility to display the Always on Display according to a schedule, which was not possible with older ColorOS versions until now.

If the schedule is used, the Always on Display (AoD) is only displayed at the specified time.

Android 10 (ColorOS 7.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Display & brightness
Step 3:  Tap on  Always-On Display
Step 4:  Enable or Disable  Schedule time
  1. Open the Settings
  2. Tap on Display & brightness
  3. Tap on Always-On Display
  4. Enable or Disable Schedule time

Oppo Instructions