Ironically, this is about going to bed early. See, it's 10:40p, and I'm getting up tomorrow at 6:00. So I'm looking at about 7 hours of sleep. This is perfect. But, that is only if I'm asleep in the next twenty minutes. I know how long it takes to get ready to leave in the morning. If I want bacon and eggs, a shower, and coffee, I need a little over thirty minutes, but its rushed. An hour is better, and relaxing.
But I don't know how long it takes to get ready for bed. If I plan to wake up early, I need to get to bed at the right time. If I set a bed time, I need a "start getting ready for bed" time. And THAT magic time currently escapes me. But if I set a time to wake up in the morning, I should set a time to go to sleep, as well.
If you can track it, you can change it. I've got the means to record this information - all that is left is for me to use it. Isn't this true in so many areas of life? We have the tools to accomplish incredible things at our finger tips, yet we use none of them.