You can track how much you sleep using your TomTom Spark or Runner 2 watch.
We measure sleep based on motion and we make an assumption that when you are not moving after a certain time in the afternoon, you are asleep.
The day 'resets' at 16:00 and we start counting a new 'night' at that point.
Activity Tracking Accuracy
Activity tracking aims to provide information to encourage an active and healthy lifestyle. Your TomTom GPS watch uses sensors that track your movement. The data and information provided is intended as a close estimation of your activity, but may not be completely accurate, including step, sleep, distance and calorie data.