Are you a night owl?  do you tend to stay up until late at night?
Yes, I really am a night owl.  I usually stay up too late and am tired the next day.
Me too..I just can't go to sleep early it seems.  The opposite of a night owl is a early bird.  someone who wakes early and goes to bed early. 
I would not consider myself an early bird, besides the weekdays when I have to get up early to go to work.  I am not disciplined in going to bed early.
In many different countries especially Scandinavia early birds are called "A people" and night owls are called "B people"