private function getTagDate($tagName)
    {
        /** @var \Platformsh\Cli\Service\Git $git */
        $git = $this->getService('git');
        $date = $git->execute(['log', '-1', '--format=%aI', 'refs/tags/' . $tagName]);

        return is_string($date) ? strtotime(trim($date)) : false;
    }