Your Philips health watch tracks how long it takes you to fall asleep as well as the time you are awake during the night. This gives you an indication of the time you've actually slept - your sleep efficiency. Normal sleep efficiency is about 85% or higher. We recommend you not to make assessments about sleep in less than 4-7 days. It is normal for some people to have an off night or two during the week. In addition to your sleep efficiency, it is also important to make sure you get the recommended amount of sleep, which can vary for each person. You can see the data from your sleep in the Philips HealthSuite health app, once the health watch syncs.
Keep in mind that not everybody needs the recommended hours of sleep. How you feel during the day and how much energy you have is just as important. Try to find out how many hours of sleep are needed for you, but aim for the recommended amount until you know for sure!