Mi Bedside Lamp costumize

How do I change the written scene?
I’d like the “sunset” scene not to run for 10 minutes, but for 30 or 40 minutes. How can this be achieved?
Or is there any other way to turn the light on at a given time and to reduce the brightness evenly to 0 under the bidet I have set?

Please have a try with Customization, you can create scene by yourself.