ปัญหาการใช้งาน function DateTimeDiff รูปแบบเวลามันออกมาเป็นทศนิยมครับ ช่วยดูให้ทีครับ

function DateTimeDiff($strDateTime1,$strDateTime2){
		return (strtotime($strDateTime2) - strtotime($strDateTime1))/  ( 60 * 60 ); 
	 }

$date_this = date("Y-m-d H:i");
$date_end1 = $func->getTable_name("tb_admin","poll_time","username","admin");
$date_end = substr ($date_end1,0,16);
echo strlen($date_this)."  ||  ";
echo strlen($date_end)."<br>";
$time_end = DateTimeDiff($date_this,$date_end);
echo "time_end".$time_end."<br>";
echo "date_this".$date_this."<br>";
echo "date_end".$date_end."<br>";
if($time_end <= 0){
	$sql = "update tb_admin set poll_sta ='2' 
				where username = 'admin'";
	$result = mysql_db_query($db,$sql);
}
echo "Date Time Diff = ".DateTimeDiff("2008-08-01 00:00","2008-08-01 19:00")."<br>";