PHP - Number Format And Rounding

|  id          | int(4)       | NO   | PRI | NULL    | auto_increment |
| user_id     | int(4)       | NO   |     | NULL    |                |
| recipient   | varchar(30)  | NO   |     | NULL    |                |
| subject     | varchar(25)  | YES  |     | NULL    |                |
| cc_email    | varchar(30)  | YES  |     | NULL    |                |
| reply       | varchar(20)  | YES  |     | NULL    |                |
| location    | varchar(50)  | YES  |     | NULL    |                |
| stationery  | varchar(40)  | YES  |     | NULL    |                |
| ink_color   | varchar(12)  | YES  |     | NULL    |                |
| fontchosen  | varchar(30)  | YES  |     | NULL    |                |
| message     | varchar(500) | NO   |     | NULL    |                |
| attachment  | varchar(40)  | YES  |     | NULL    |                |
| messageDate | datetime     | YES  |     | NULL    |        

            $params = array(                 
               ':user_id' => $userid,                 
               ':recipient' => $this->message_vars['recipient'],                 
               ':subject' => $this->message_vars['subject'],                 
               ':cc_email' => $this->message_vars['cc_email'],                 
               ':reply' => $this->message_vars['reply'],                 
               ':location' => $this->message_vars['location'],                 
               ':stationery' => $this->message_vars['stationery'],                 
               ':ink_color' => $this->message_vars['ink_color'],                 
               ':fontchosen' => $this->message_vars['fontchosen'],                 
               ':message' => $messageInput,                 
               ':attachment' => $this->message_vars['attachment'],                 
               ':messageDate' => $date             );

$sql = "INSERT INTO messages (user_id,recipient, subject, cc_email, reply, location,stationery, ink_color, fontchosen, message,attachment) VALUES( $userid, :recipient, :subject, :cc_email, :reply, :location, :stationery, :ink_color, :fontchosen, $messageInput, :attachment, $date);";

And lastly, here is how I am calling it:
            $dbh = parent::$dbh;             
           $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);              
           if (empty($dbh))    return false;             
                  $stmt = $dbh->prepare($sql);             
                 $stmt->execute($params) or die(print_r($stmt->errorInfo(), true));              
           if (!$stmt) {    print_r($dbh->errorInfo());              }

Hello All, 
  Need an advise in finishing this task please. 
 

function convertTimeFormat($time12Hour) {
// Initialized required variable to an empty string.
		$time24Hour = ""; 

// Used explode() function to break the string into an array and stored its value in $Split variable. 
		$Split = explode(":",$time12Hour); // print_r(explode (":", $time12Hour)); => Array ( [0] => 09 [1] => 50 [2] => 08AM )

// Retrieved only "hour" from the array and stored in $Hour variable. 
		$Hour = $Split[0];   

    $Split[2] = substr($Split[2],0,2);

// Used stripos() function to find the position of the first occurrence of a string inside another string.	
		if($Hour == '12' && strpos($time12Hour,"AM")!== FALSE) {
			// Code here 
		} elseif(strpos($time12Hour,"PM")!== FALSE && $Hour != "12") {
			// code here
		}
		return  $time24Hour;
	}
	$time12Hour = "09:50:08AM";
	$result = convertTimeFormat($time12Hour);
	print_r($result); 

/*
Input : "09:50:08AM";
Output : "21:50:08PM";
*/