คำนวณระยะห่าง (วัน) อย่างไรคะ อยากเขียน php ให้หาระยะเวลาเป็นวัน (ตามตัวอย่างเป็น 2 วัน) ต้องเขียนยังไงคะ

<?php
	 function DateDiff($strDate1,$strDate2)
	 {
				return (strtotime($strDate2) - strtotime($strDate1))/  ( 60 * 60 * 24 );  // 1 day = 60*60*24
	 }
	 function TimeDiff($strTime1,$strTime2)
	 {
				return (strtotime($strTime2) - strtotime($strTime1))/  ( 60 * 60 ); // 1 Hour =  60*60
	 }
	 function DateTimeDiff($strDateTime1,$strDateTime2)
	 {
				return (strtotime($strDateTime2) - strtotime($strDateTime1))/  ( 60 * 60 ); // 1 Hour =  60*60
	 }

	 echo "Date Diff = ".DateDiff("2008-08-01","2008-08-31")."<br>";
	 echo "Time Diff = ".TimeDiff("00:00","19:00")."<br>";
	 echo "Date Time Diff = ".DateTimeDiff("2008-08-01 00:00","2008-08-01 19:00")."<br>";
?>

<?
function CalDate($time1,$time2){
 	//Convert date to formate Timpstamp
 	$time1=strtotime($time1);
	$time2=strtotime($time2);
	
	//$diffdate=$time1-$time2
	$distanceInSeconds = round(abs($time2 - $time1)); //จะได้เป็นวินาที
	$distanceInMinutes = round($distanceInSeconds / 60); //แปลงจากวินาทีเป็นนาที
	
	$days = floor(abs($distanceInMinutes / 1440)); 
	$hours = floor(fmod($distanceInMinutes, 1440)/60); 
	$minutes = floor(fmod($distanceInMinutes, 60));
	

	return " Days:".$days ." Hour:" .$hours ." Minute:".$minutes;
 
 }
?>

<?php
 
	$strStartDate = "2011-08-01";
	$strEndDate = "2011-08-15";
	
	$intWorkDay = 0;
	$intHoliday = 0;
	$intTotalDay = ((strtotime($strEndDate) - strtotime($strStartDate))/  ( 60 * 60 * 24 )) + 1; 

	while (strtotime($strStartDate) <= strtotime($strEndDate)) {
		
		$DayOfWeek = date("w", strtotime($strStartDate));
		if($DayOfWeek == 0 or $DayOfWeek ==6)  // 0 = Sunday, 6 = Saturday;
		{
			$intHoliday++;
			echo "$strStartDate = <font color=red>Holiday</font><br>";
		}
		else
		{
			$intWorkDay++;
			echo "$strStartDate = <b>Work Day</b><br>";
		}
		//$DayOfWeek = date("l", strtotime($strStartDate)); // return Sunday, Monday,Tuesday....

		$strStartDate = date ("Y-m-d", strtotime("+1 day", strtotime($strStartDate)));
	}

	echo "<hr>";
	echo "<br>Total Day = $intTotalDay";
	echo "<br>Work Day = $intWorkDay";
	echo "<br>Holiday = $intHoliday";
?>