When does school start?

My kids are driving me crazy!! I can not wait for school to start! I don't think the summer is ever going to end. My oldest who is 12 totally does not listen to me. He acts like I don't even say anything. He has a 'whatever' attitude about everything and it is about to make me flip out! My middle son who is 9 fights constantly with the 4 year old and I can't stand it. Every single word out of his mouth is in complete contradiction to what his brother is saying and it does not matter what it is. The youngest could say that the sky is blue and #2 would say 'no it isn't!' They are slowly making me lose my mind. And the youngest, well, he imitates everything that his brothers do, and needless to say, they are not teaching him good things with attitudes like this. I always feel bad for yelling at them all the time and then I sit back and think to myself, well, if they were listening to me I wouldn't be yelling at them! I really try to be patient with them and it never fails that they start fighting and ignoring me and I end up getting really mad and yelling. Granted, I do not start off yelling, this comes after about 20 times saying the same thing or listening to bickering for 30 minutes, that I want to pull every hair out of my head! Seriously. School can not start soon enough.