Sept 1. noon-sunset it lasts till late sept or first week of oct then opens again twice more for a few weeks or something like that.
I usually hunt them 2-3 times a season and have better hunts later in the year. Last year we slaughtered them on a but grass field next to a new clear cut. Ran out of shells and had to dig around in the truck for enough to get a limit. Damn I love those tasty little suckers.