So one thing is for sure: We don't know what the author meant, because we can't ask him or her.
I remember my professors always having really strange interpretations of literature, and I thought, "Where did they get THAT meaning???" You can invent anything, I guess, if you don't know the author's intentions for sure.
As for this 'sunny night' sentence, the last post-er's idea (Seoul, Korea) is my favorite! Very poetic. I might even use it as an example in my ELL class this year.