Imagine a Saturday morning when you open your eyes naturally (no alarm) and how peaceful that feels. Now imagine when your alarm goes off Monday morning and how hard it is to get out of bed. The interesting thing is that it’s not necessarily because you got less sleep. In fact, it has more to do with where you are in your sleep cycle when you wake up.

In this article, we explore the phases of your natural sleep cycle, when to sleep, and how to wake up refreshed. We look at how many hours of sleep are recommended and how to use a sleep cycle calculator (such as the one here) to find the best time to wake up.