 It runs 24-7 until Labor Day. And by doing so, it basically reduces the populations of mosquitoes over those days that it's on. And it's amazing. It takes about three weeks to get started and get caught up where you didn't notice anything. But we live in the mosquito capital of the world, New Jersey. I'm telling you, I've got a swamp that's 500 yards from my back door. I thought it was the tomato capital.