Well but there's a lot more to sleep than time. I know waking up 20 minutes earlier then my bodies decided wake time creates much more than 20 minutes of groggi

Well but there's a lot more to sleep than time. I know waking up 20 minutes earlier then my bodies decided wake time creates much more than 20 minutes of grogginess. Waking up n minutes before sleep Cycle end might be okay for some people but in the times I've had to set my alarm a little earlier, the time of waking makes a difference all day. Now, if you're already not sleeping enough for your body and get woken up groggy and tired by an alarm every morning, that 20 minutes probably won't kill you faster than the lessened sleep you already get.