How to calculate the difference of datetime field and now in PHP?

$diff = abs(strtotime($date2) - strtotime($date1));

Here is the answer :)

$now = new DateTime();
$date = new DateTime("2012-05-03 17:34:01");

echo $date->diff($now)->format("%d days, %h hours and %i minutes");

date_diff:

$datetime1 = new DateTime('2009-10-11');
$datetime2 = new DateTime("now");
$interval = $datetime1->diff($datetime2);
echo $interval->format('%R%a days');