automatically add time to date if no exists

function check_time($date, $time = null){
    if ($time) {
        return $date.' '.$time;
    }
    return $date.' '.date('H:i');
}
    
check_time('2020-02-24'); // 2020-02-24 23:48
check_time('2020-02-24', '20:00'); // 2020-02-24 20:00