The day before and the day you start the reason i say put it out before is if a buck does cruse thru and he smells it he will think there is a hot doe in the area and will probly revisit the area to keep a check to see if he can find her and it might be the sameday your there thats why i would put some out the day i started hunting so it will be some fresh scent and if he has already smelled it the day before and he gets a wiff of a hot scent he will come looking.so i would put some out before and the day of good luck.

As buckhunter pointed out, putting scent out early can result in some surprises. I drag a scent rag to my stand. One day, while setting up a ground blind I heard some noise behind me. I was using a red headlight. I turned around and was face to face with a buck only a few feet away. Shocked both of us. I must have gasped. He skedaddled, probably not even knowing what frightened him.

Putting some scent on the bottoms of your shoes works well, just make sure that you keep and eye on the trail you walked in on. You may see a buck following you in with his nose to the ground.

day before and drag some on rag behind you as you go.