How to get up without an alarm clock

(Disclaimer: I keep an alarm clock as backup. But most days I can wake up before it rings.)

Sleep is one of my obsessions. For most of my life, I had trouble waking up on time for school or work. A few years ago I discovered that I could wake up on time without an alarm clock (or more accurately, wake up before it rings).

How to get up without an alarm clock:

1. Find out how much sleep you need for an active day (say 8 hours of sleep)
2. Find out the time you need to wake up every day (say 0700)
3. Subtract time (1) from time (2) to get your bedtime (0700 - 8 hours = 2300)
4. Start sleeping regularly at your bedtime (2300) and keep an alarm for your wakeup time (0700).

Is it not elementary, my dear Watson? Do this for a week or two and soon you will find yourself awake before the alarm clock rings.

Both you and I know very well that there are devils hidden in this simple method. One of them is the bedtime. A consistent bedtime is required for this to work ;-)