php 根据星期获取月份日期

/**
         * 根据星期获取月份日期
         * @param  int $weenNum 星期0-6
         * @return array $days  返回日期数组
         */
        public function getDateByWeek($weekNum,$month,$year)
        {
            $totalDays=date('t',strtotime(mktime(0,0,0,$month,1,$year)));//计算月份总天数
            $days=array();
            for($day=1;$day<=$totalDays;$day++)
            {
                $mkTime=mktime(0,0,0,$month,$day,$year);
                if(date('w',$mkTime)==$weekNum){
                    $days[]=date('Y-m-d',$mkTime);
                }
            }
            return $days;
        }
//该片段来自于http://outofmemory.cn