You will have to look into [strtotime()][1]. I'd imagine your final code would look something like this:
$dateVariable = strtotime('2010-04-09');//your date variable goes here
$date_after_7_days = date('Y-m-d', strtotime('+7 days', $dateVariable));
echo $date_after_7_days;
[Live Demo][2]
[1]: http://php.net/manual/en/function.strtotime.php
[2]: https://eval.in/734924
You will have to look into [strtotime()][1]. I'd imagine your final code would look something like this:
$future_date = "April 16,2010";
$seconds = strtotime($future_date) - time();
$days = $seconds /(60 * 60* 24);
echo $days; //Returns "6.0212962962963"
[1]: http://php.net/manual/en/function.strtotime.php
