not sure the best time is others will have to fill you in on that...buttttt, one thing i do know is that rattling antlers works best when you have a sound buck to doe ratio....on our property we used to have an outrageous number of does compared to the bucks, thus rattling was never successful because the bucks never had to worry about competition as there was always a plethora of does in any given area....soooo, do a little scouting of the area in which you'll be hunting to assure that rattling will be successful