From Rafa on 2015/06/01 11:28:02 +0000
You especify the time you want to achieve and the app automatically set the clock earlier each morning.
Example:
You want to wake up at 7 but you are stuck at 8. You set your goal time (7) and giving a start time (8) each morning the alarm would wake up you minutes earlier which can be adjustable by yourself, for example 15 minutes.
So It will go like this:
Start time: 8
Goal time: 7
Day 1: 7:45
Day 2: 7:30
Day 3: 7:15
Day 4 (Achieved!): 7
Sorry my poor english 
Copied from original feature request: http://urbandroid.uservoice.com/forums/264867-sleep-as-android/suggestions/8187831-achieving-your-dreamt-wake-up-time