if和switch語句

<?php 
      date_default_timezone_set("Etc/GMT-8");
      echo"當前時間是：".date("Y-m-d H:i:s",time())."<br>";
      
      $hour=date("H");
      if($hour<6){
      	echo"凌晨好!";
      }elseif ($hour<9){
      	echo"早上好";
      }elseif($hour<12){
      	echo"上午好"; 	
      }elseif($hour<14){
      	echo"中午好"; 	
      }elseif($hour<17){
      	echo"下午好"; 	
      }elseif($hour<19){
      	echo"傍晚好"; 	
      }elseif($hour<22){
      	echo"晚上好"; 	
      }else{
      	echo"夜裏好";
      }
      echo"<br>";
      $week=date("D");
      switch ($week){
      	case "Mon":
      		echo "星期一";
      		break;
      	case"Tue":
      		echo"星期二";
      		break;
      	case"Wed":
      		echo"星期三";
      		break;
      	case"Thu":
      		echo"星期四";
      		break;
      	case"Fri":
      		echo"星期五";
      		break;
      	case"Sat":
      		echo"星期六";
      		break;
      	case"Sun":
      		echo"星期日";
      		break;
      }
   ?>