I like to get to where I will start shock calling about 30 minutes before first inkling of light. I'll listen for hens or gobbleing, and if I do not hear any by say 30 minutes after daybreak, I will shock call ... and hopefully the chase will be on !! If I have a gobbler roosted, which I was not able to do this year, I will try to slip in near (50 -100 yards or so depending on where I think he might pitch) the roost around a hour before daybreak and take a seat, being as quiet as I can and with no flash light !