Moon phase based internal sky light

Intetnal sky light is equal to 15 in noon/day, and it is qeual to 4 in midnight. Is there a way to reduce it in each moon phase? For example, internal sky lights are equal to these values during this phases of the moon:
Full moon: 4
Waning gibbous: 3
Last quarter: 2
Waning crescent: 1
New moon: 0
İs it possible to do that? Or maybe is there another way to do sky gets darker in each phase?