php判断某个时间是否在一个时间段内

/**
 * 判断当前时间是否在时间段内
 * @return bool
 */
public function get_time(){
    $Day = date('Y-m-d ',time());
    $timeBegin = strtotime($Day."15:00".":00");
    $timeEnd = strtotime($Day."21:00".":00");
    $curr_time = time();
    if($curr_time >= $timeBegin && $curr_time <= $timeEnd){
        return true;
    }
    return false;
}