in Thoreau’s Journal:

I have not put darkness, duskiness enough into my night and moonlight walks. Every sentence should contain some twilight or night. At least the light in it should be the yellow or creamy light of the moon, or the fine beams of stars, and not the white light of day. The peculiar dusky serenity of the sentences must not allow the reader to forget that it is evening or night, without my saying that it is dark.