Trees in night are bright

We are facing a problem with our lights.
We are working on a day/night cycle and we found out that our trees and other meshes are still bright even during the night.

Here is a screen:

On the map we have a light source (intensity 0), a skysphere and a skylight with intensity 0.
We just set the skylight intensity under 0 but have weird colors.
No postprocessing here

Thats a real problem for us :confused:
Thanks for the help!

I think if you have baked lighting you need lighing scenarios to do that. I am not profy so I might be wrong.