It’s as follows : –

$year=2013;
$month=04;
$date=12;
$newdate=date('Y-m-d H:i:s', strtotime($year."-".$month."-".$date." 00:00:00" . ' + 1 day'));

O/p :-

$new date will be “2013-04-13 00:00:00“