yii\validators\DateValidator::parseDateValueIntl PHP Method

    private function parseDateValueIntl($value, $format)
    {
        if (isset($this->_dateFormats[$format])) {
            if ($this->type === self::TYPE_DATE) {
                $formatter = new IntlDateFormatter($this->locale, $this->_dateFormats[$format], IntlDateFormatter::NONE, 'UTC');
            } elseif ($this->type === self::TYPE_DATETIME) {
                $formatter = new IntlDateFormatter($this->locale, $this->_dateFormats[$format], $this->_dateFormats[$format], $this->timeZone);
            } elseif ($this->type === self::TYPE_TIME) {
                $formatter = new IntlDateFormatter($this->locale, IntlDateFormatter::NONE, $this->_dateFormats[$format], $this->timeZone);
            } else {
                throw new InvalidConfigException('Unknown validation type set for DateValidator::$type: ' . $this->type);
            }
        } else {
            // if no time was provided in the format string set time to 0 to get a simple date timestamp
            $hasTimeInfo = strpbrk($format, 'ahHkKmsSA') !== false;
            $formatter = new IntlDateFormatter($this->locale, IntlDateFormatter::NONE, IntlDateFormatter::NONE, $hasTimeInfo ? $this->timeZone : 'UTC', null, $format);
        }
        // enable strict parsing to avoid getting invalid date values
        $formatter->setLenient(false);
        // There should not be a warning thrown by parse() but this seems to be the case on windows so we suppress it here
        // See https://github.com/yiisoft/yii2/issues/5962 and https://bugs.php.net/bug.php?id=68528
        $parsePos = 0;
        $parsedDate = @$formatter->parse($value, $parsePos);
        if ($parsedDate === false || $parsePos !== mb_strlen($value, Yii::$app ? Yii::$app->charset : 'UTF-8')) {
            return false;
        }
        return $parsedDate;
    }