PHP date showing '1970-01-01 ' after conversion

Question

I have a form in which date format is dd/mm/yyyy . For searching database , I hanverted the date format to yyyy-mm-dd . But when I echo

Answer 1

$date1 = $_REQUEST['date'];

if($date1) {
    $date1 = date( 'Y-m-d', strtotime($date1));
} else {
    $date1 = '';
}

This will display properly when there is a valid date() in $date and display nothing if not.
Solved the issue for me.