PHP - Date difference function

function DateDiff($interval, $date1, $date2)
{
// Function roughly equivalent to the ASP "DateDiff" function

//convert the dates into timestamps
$date1 = strtotime($date1);
$date2 = strtotime($date2);
$seconds = $date2 - $date1;

//if $date1 > $date2
//change substraction order
//convert the diff to +ve integer
if ($seconds < tmp =" $date1;" date1 =" $date2;" date2 =" $tmp;" seconds =" 0-$seconds;" interval ="="'y'" interval="="'m')" date1 =" date(" date2=" date(" time1 =" (date('H',$date1)*3600)" time2 =" (date('H',$date2)*3600)" diff =" $year2"> $month2) {
$diff -= 1;
} elseif($month1 == $month2) {
if($day1 > $day2) {
$diff -= 1;
} elseif($day1 == $day2) {
if($time1 > $time2) {
$diff -= 1;
}
}
}
break;
case "m":
list($year1, $month1, $day1) = split('-', $date1);
list($year2, $month2, $day2) = split('-',$date2);
$time1 = (date('H',$date1)*3600) + (date('i',$date1)*60) + (date('s',$date1));
$time2 = (date('H',$date2)*3600) + (date('i',$date2)*60) + (date('s',$date2));
$diff = ($year2 * 12 + $month2) - ($year1 * 12 + $month1);
if($day1 > $day2) {
$diff -= 1;
} elseif($day1 == $day2) {
if($time1 > $time2) {
$diff -= 1;
}
}
break;
case "w":
// Only simple seconds calculation needed from here on
$diff = floor($seconds / 604800);
break;
case "d":
$diff = floor($seconds / 86400);
break;
case "h":
$diff = floor($seconds / 3600);
break;
case "i":
$diff = floor($seconds / 60);
break;
case "s":
$diff = $seconds;
break;
}

return $diff;
}

Disclaimer: Any code or advice given is for instructional purposes only. We will not be responsible for any loss or damage caused by using this script.