View your sleep history in Health on iPod touch
Sleep data in the Health app 
provides insight into your sleep habits.
Tap Browse at the bottom right, then tap Sleep.
Do any of the following:
View sleep data by week or month: Tap a tab at the top of the screen.
Change the time span displayed in the graph: Swipe the graph left or right.
View the details for a day: Tap the column for the day.
Manually add sleep data: Tap Add Data in the top-right corner of the screen.
Get cumulative sleep data: Tap Show More Sleep Data.
If you set up a sleep schedule, Time in Bed reflects the period you’re lying in bed with the intention to sleep. iPod touch automatically tracks your time in bed by analyzing when you pick up and use your iPod touch. You can also tap Options at the bottom of the Sleep Focus screen, turn off Track Time in Bed with iPod touch, and manually enter your own estimated time in bed. Or you can use a sleep tracker app or a connected sleep monitor to help you determine the amount of time you’re in bed.
For information about collecting data from sleep trackers or monitors, see Health data collected from other apps and devices.