I read somewhere once that there are two patterns of sleeping:
1) people who are tired in the end of the day and sleep early; they get up early and energetic and loose energy during the activity of the day;
2) peolpe who sleep late and wake up slowly; they gain energy during the day and so they are at the top when others go to sleep.
My questions are?
What makes an early sleeper? Being an S, a J or both?
What makes a late sleeper? Being an N, a P or both?
What is your case?