I totally identify with your being "a different person from day to night". I am 75% better at night and that only makes my sleep-shifted hours worse (go to bed ungodly late early AM). It seems like the world is totally opposite. Just when everyone is getting tired and going to bed it is then that I can do anything. Although, have noticed at around 8pm am getting tired and then it passes. Thinking it may be akin to most people's "afternoon slump". Also when it is COOL I have way more energy and can think better as well.