When do airlines REALLY load AWARD seats?
I have heard calling 330 days out is the best time and I have heard 331 days out.
If you have done this often, is 331 fairly standard? Do some airlines have totally different timeframes? Do some not show any awards at 330-331 days, but at some vague unknown point?
I have no experience in doing this but have read about people calling at midnight on the 'right day' to get their award seats.
What about non-US based airlines? Are their guidelines similar? I have called a few times lately for coach seats 331 days out and found nothing and gotten vague answers from agents. I am trying to plan ahead so I can get flights that I want. My dates are VERY flexible, but I hate to lock in flights/routings that are 3rd or 4th choice 330 days out 
Which airlines are you familiar with? What is the 'right date' to call? Or is that a myth and some airlines don't load award seats until they 'feel like it'?
Help me demystify 