About 15 minutes.
Deer knows every tree, every stump, every creek and spring, every trail and every nook and cranny in the woods. Their noses are 1000 times stronger then yours or mine. Their sense of danger is always on alert.
The funny thing is - deer sees in black and white.
Deer doesn't pay attention to objects, they look for movements.
If they see something out of place, they will act like comedians, trying to amuse you to the point of where you will smile, move your hands, arms, feet, legs, eyes, head.
If I had a nickle for every time that I was sitting in the woods and a doe walked up to me and started spinning her head around in a circle - trying to get me to move. Or stomping her foot to let the other deer know - hey something is not right. Or just stood patiently - waiting for me to move first. How many times have you hunted deer in Pennsylvania in the rifle season in December and took off your gloves to shoot a deer and then it held up behind a bush and after 15 minutes your hands got so froze that you thought that your fingers were going to fall off?
Only to move one finger and the deer saw it and was gone in a flash!
At the same time, you can park a pick up truck in the middle of the camp yard and go in the camp and look out the window and see three deer in the yard...