Sutta reference or teachings about Sleep timings? In a Vipassana retreat you are made to wake up at 4 am, also similar is the case in the Zen retreat. 

I have read numerous articles on advantage on waking up early. 

Are there any Sutta references or teachings of Monks or Lama or Zen master which give advise on waking up early and going to bed early?
Sutta Pitaka Vol 4 : Sutta. Ma. Mū. Mahāassapurasuttaṃ:


  What more is there to do? 
  
  You should train yourselves like this: ‘We will be committed to
  wakefulness. 
  
  
  When practicing walking and sitting meditation by day, we will
  purifying our mind from obstacles.
  In the evening, we will continue to practice walking and sitting
  meditation.
  In the middle of the night, we will lie down in the lion’s
  posture—on the right side, placing one foot on top of the
  other—mindful and aware, and focused on the time of getting up.
  In the last part of the night, we will get up and continue to
  practice walking and sitting meditation, purifying our mind from
  obstacles.’
  
  
  Now, mendicants, you might think: ‘We have conscience and prudence,
  our bodily, verbal, and mental behavior is pure, our livelihood is
  pure, our sense doors are restrained, we don’t eat too much, and we
  are committed to wakefulness. Just this much is enough …’