If you'd like to manually edit your sleep times from previous days, you can do so by following the steps below:
1. Select the "Progress" tab at bottom of the screen.
2. Choose the day you'd like to edit. (You can do so by either tapping on the specific day from the list at the bottom or by tapping directly on the purple bars from the graph at the top).
3. Use your finger to scroll and set the desired sleep time. (If you'd like to also add awake time, simply press the screen around the desired time)
4. Tap "Save" at the top right corner and you're all set.
NOTE: You can only go back and edit sleep times up to 14 days in the past.