I was thinking to do it (not only with the courtyard, but with the whole castle stage), but not now. I mean, my models aren't affected by lights, so if I make it nighttime, the only change would be the light for characters and the background texture. I would need to modify every texture in the stage to make it look as night. Even keeping the direction from lighting to be replaced by the moon, everything would need to be darkened, and the contrast between shadowed areas and lightened areas would need to be reducted.
What I mean is, if I wanted to make the nighttime version for the release, I may be some more months working before releasing >.<