PHP: calculate days between two date given (database & original)

PHP: calculate days between two date given

//from php 
$date1 = date_create('2017-10-10');
$date2 = date_create('2017-10-15');
$diff = date_diff($date1,$date2);

echo $diff->format("%R%a days");   // +14 days - %R is +/- | %a is number
//from database to php
$y = date('Y', strtotime($desc['gep_startdate']));
$m = date('n', strtotime($desc['gep_startdate']));
$date1 = date_create($desc['gep_startdate']);
$date2 = date_create(date($y.'-'.$m.'-27'));
$diff = date_diff($date1,$date2);
echo $diff->format("%R%a days");   // +20 days