Every person has a different sleep cycle, and therefore we all have different needs when it comes to sleeping well. To be able to wake up feeling well rested and not tired, it is important that one knows how many hours of sleep they need. In order to find that out, Justin would need to go to sleep at a normal time, not too early nor too late. Adding to this, Justin needs to put off his alarm clock, at least for the first two nights. If he is afraid of not waking up on time due to the lack of an alarm clock, he should do this test when he does not need to wake up early, for instance during the weekends when there is no school. After waking up naturally for two consecutive days, Justin can go back to set an alarm clock every night, and this time he should consider how many hours did he sleep for the previous two days. By knowing this, he should be able to sleep the amount of time that his body needs in order to feel rested.