The Sleep Performance page provides a summary of the previous night’s sleep, highlighting the Sleep Performance score, which is the Hours of Sleep compared to the amount of Sleep Needed.
This page also provides statistics (Time in Bed, Disturbances, and Latency) for that night, relative to the average of the last two weeks.
You can access more detailed statistics by tapping Hours of Sleep.
To access the Sleep page, simply swipe left three times from the One Day Overview. You can also access previous days through the Calendar view.