<?php
function valid_date($date, $format = 'Y-m-d H:i:s') {
    $dt = DateTime::createFromFormat($format, $date);
    return $dt && $dt->format($format) === $date;
}

var_dump(valid_date('2025-06-06 00:00:00'));  // true
var_dump(valid_date('2025-06-06 24:00:00'));  // false
var_dump(valid_date('2025-06-06 00:60:00'));  // false
var_dump(valid_date('2025-06-06 00:00:60'));  // false
var_dump(valid_date('2025-6-06 00:00:00'));    // false
var_dump(valid_date('2025-06-6 00:00:00'));    // false
var_dump(valid_date('2025-13-06 00:00:00'));  // false
var_dump(valid_date('2025-06-31 00:00:00'));  // false
var_dump(valid_date('오늘은 2025년 6월 6일이고 현재 시간은 00시 00분 00초입니다.'));  // false
?>