The sunrise and sunset times before they go out? Official shooting light is 1/2 hour before and after these times. Do you check and remember to check in the field when you can "officially" shoot. What about legal shooting times in the thickest of crap on a cloudy morning, or the edge of a field just past legal light when their isnt a cloud in the sky and you actually have better light than the previous scenario, or do you just use your best judgement? Have you ever gotten out of your stand a few minutes early to prevent the situation where deer could come in but not be within shooting range. Then you have to choose either sit until the deer moves off, or getting down and spooking them?