What EvilEye and I were trying to get at is that your current lighting can easily imply it's daylight, even with the sky. Look, here I did a quick swap of the sky with a crappy "daytime" color scheme and nothing looks wrong with it.
I think that's fairly problematic.
Have you tried having the trees fade to a black silhouette? I think it fits more with a night scene, even with the moon, especially since the moon is behind the trees it doesn't make much sense that they're so lit.
EvilEye's blue highlights also help to imply the cool light of the moon, giving more to imply night light when warmer highlights imply sunlight.