The best time is waking up before sun is up. to do that it will need to sleep early. if anyone do that his/her will feel fresh and get much more time to do lots of work too.
I wouldn't know...I never wake up before 11am lol jk...I'de say between 6am and 7 am as far as keeping a nice healthy sleep schedule.
I thins before the sun rise. it is best time to wake up a body from physical point of view to keep it fit and healthy.
6 AM is always best. Do some simple exercises first at least for 10 minutes instead of going to bath.