I was also thinking it might be difficult to keep up a 5pm sleep time during the summer months when the sun sets later. But if you had a sound-proof bedroom that was pitch dark (some crazy shades that blocked all light), then I would imagine that would help a lot.
An 8pm-4am sleep time sounds more manageable... although the 5pm-midnight sleep schedule is such a talking point. :)
An 8pm-4am sleep time sounds more manageable... although the 5pm-midnight sleep schedule is such a talking point. :)