format($this->dateFormat ?: 'Y-m-d H:i:s'); } /** * Check is valid date string * * @see https://stackoverflow.com/questions/19271381/correctly-determine-if-date-string-is-a-valid-date-in-that-format * @param $name * @param string $format * @return bool */ public function isValidDate($name, $format = 'Y-m-d H:i:s'): bool { $date = $this->getRawOriginal($name); $d = \DateTime::createFromFormat($format, $date); // The Y ( 4 digits year ) returns TRUE for any integer with any number of digits so changing the comparison from == to === fixes the issue. return $d && $d->format($format) === $date; } }