Nightbird vs Early risers - What sort of person are you?

#1 Not a nightbird, not an early riser too.
#2 Sleep during 12:30 AM- 06:30 AM.
#3 Reasons- A) Library closes at 11 PM. Want to stay till the end. Better to study when awake than to struggle in waking up in the early morning. 
B) This has been lifestyle since early childhood.