//生成前六个月
	function to_sex_month($mun){
        $arr = array();
	        for($i = 1;$i <= $mun; ++$i){
	        $t = strtotime("-$i month");
	        $arr[] = date('Y-m',$t);
        }
        return $arr;
	}
	//生成前六个月时间戳
	function to_sex_months($mun){
        $arr = array();
	        for($i = 1;$i <= $mun; ++$i){
	        $t = strtotime("-$i month");
	        $lastDay = date('Y-m-',$t).date('t',$t);
	        $arr[] = explode('/',strtotime(date('Y-m-01',$t)).'/'.strtotime($lastDay));
        }
        return $arr;
	}

to_sex_month(6);