I woke up at 2:30 AM. It's better. I have woke up at 11:30 once.
My sleeping cycle is now tribble. At 8:00 PM, I go to bed, and I wake up at 2:30 AM. My ideal sleeping time is from 11:00 PM to 6:00 AM. I wrote on this blog that my sleeping cycle is 23 hour. My wake-up-time isn't fit social life.