Normally I try to get set-up and let the area "quieten" down 30 minutes or so before the fist crack of light. However, if I am headed into an area that I have not yet figured out a "quiet" way in, I'll time it so that I am able to barely see by the time I am within 1/4 mile or so of where I want to set up. That way I can at least try to avoid making a ton of noise going in. This puts me setting up right at decent light. That is not usually a good thing when I am using a climber. But think I miss too much "prime" time when I decide to wait a bit. Frankly I have very seldom had deer come by before 1 or more hours after decent shooting light, even when I am in way before light. It has happened over these past 50+/- years, but probably not more than 15 - 20 times.