Fireworks

Fireworks set off outside my window,lasting for about 20 minutes.i am not sure what it is for.But 4 days later,on 1st of October, it is National day for China,and it is 60 anniversary,so there will be a ceremonious celebration for that in Beijing.is this firework a rehearse?i have no idea,but 20 minutes fireworks show is not bad for me.