I have never kept an hourly record of my mental alertness until now. During this three-day period, I noticed that my alertness follows a certain path. Thursday and Friday I noticed that in the morning from 7:00 to 8:00 I was extremely sleepy, while at 9:00 I was a little sleepy, by 10:00 I was extremely alert and efficient until about 3:00 , where I slowed down a little more, and that was until I at least had lunch. In the late afternoon, around 7:00-8:00 p.m., I was alert again until I sat down and did my homework, around 9:00-10:00 p.m., I was already tired and sleepy, because of all the the tasks of the day. My third day was Saturday and I noticed my circadian rhythm was different. I slept better at night, without any disturbance. I woke up late around 11am and once up I was somewhat alert, by midday I was extremely alert and efficient. I didn't feel any drowsiness or fatigue during the day until about 11 p.m. However, I was able to stay awake and go to bed