The time you wake is not as important as the time you return to sleep. You want to return to sleep when you know you should be entering a long, stable REM cycle. You can adjust the time you awake, or the length of time you stay awake. Take a few nights trying to pin down when your best dreams happen.

Sometimes it is easier not to overthink it. Our bodies are sensitive to all sorts of stuff, and are not 100% predictable. Just guess, and adjust accordingly the next night