well there is no for sure answer to this question as there is NO sure time of yr it works
deer are individuals, and some will respond to noises like rattling and some will not
deer are curious creatures too and will often come and investigate sounds ANY time of the yr, just as well as sounds will SCARE them at any time of the yr!
I have had some success with rattling calls, BUT only in places where there is a decent amount of OLDER class bucks
seems to me it takes a few yrs for them to really respond to them with the THOUGHT of it meaning breeding bucks fighting, and not again, just a curious deer coming to noises and wanting to MAYBE see what the fuss is about!
other times I have had dozens of deer in food plots, close enough to hear things and never so much as raise a ear or seem to care about the sounds
and worse yet I have see it scare deer off that WERE in view after rattling, both LARGE bucks and small one's!
like scents and all calls,
some times they help, sometimes they do NOTHING, some times they scare things away!