The Wake-up Stats only record data when your iPhone is docked and the app is running. Therefore, docking is the beginning of the time line on the summary page and undocking is the end of the time line.
Each night, the system records if you use the fall-asleep function or if you simply operate the lamp manually. In the morning, your wake-up settings and number of snoozes are memorized.
Recording these events is optional, and you can choose to disable this feature in the Settings menu. This information is stored in your iPhone for six months before it gets deleted permanently.
In the morning you can choose to answer two questions and write a personal note:
These values allow you to track how you feel in the morning, and help you to understand how the Wake-up Light works for you. Answering these questions is completely optional. You can enable or disable them anytime in the Settings menu.
You can answer the questions about your waking up and sleep any time on the day following the night by clicking “Questions” in the top right-hand corner of the weekly summary, but it is most accurate if you answer them within the first half hour after waking up.
Keep in mind that this integrated Wake-up Light diary does not actually record your sleep but your routines. You may be in bed with the light off but not necessarily sleeping, or your mobile device may be docked long before your bedtime. If this happens you can record this in the personal note space.