I can tell you after 27 years of turkey hunting, 10am - 2pm is awesome for killing a tom. In the mornings on the roost they gobble for the hens to come to them, that is how nature said it was to be. They are most vocal at this time however they attract hens in those first couple of hours.

Give the hens time to get bred and off to nesting duties and around 10 they start getting lonely. If you can get a gobbler to sound off mid morning to early afternoon you have a good chance he is alone or at least with some other gobbler buddies, but most likely without hens and will be a lot easier to call in. He won't usually be as vocal though so be ready for that magical "drumming" to alert you of his incoming presence. Good Luck!!!