Magento – Magento 2 – get wrong locale which I set in system config

localemagento2

In Magento 2, I get wrong locale which I set in system config?

The first, I go to admin->set config locale is Japanese.

And then, I go to class "\Magento\Framework\Stdlib\DateTime\Timezone"

....
    /**
     * {@inheritdoc}
     */
    public function getDateFormat($type = \IntlDateFormatter::SHORT)
    {
        var_dump($this->_localeResolver->getLocale());
        return (new \IntlDateFormatter(
            $this->_localeResolver->getLocale(),
            $type,
            \IntlDateFormatter::NONE
        ))->getPattern();
    }
.......

And then I got the result: "en_US".
Did you see the same issue in your system?
If you have solution, may you help me please?