src/Composer/Repository/Vcs/GitHubDriver.php
public function getChangeDate($identifier)
    {
        if ($this->gitDriver) {
            return $this->gitDriver->getChangeDate($identifier);
        }

        $resource = $this->getApiUrl() . '/repos/'.$this->owner.'/'.$this->repository.'/commits/'.urlencode($identifier);
        $commit = JsonFile::parseJson($this->getContents($resource), $resource);

        return new \DateTime($commit['commit']['committer']['date']);
    }
public function getChangeDate($identifier)
    {
        if ($this->gitDriver) {
            return $this->gitDriver->getChangeDate($identifier);
        }

        $resource = $this->getApiUrl() . '/repos/'.$this->owner.'/'.$this->repository.'/commits/'.urlencode($identifier);
        $commit = JsonFile::parseJson($this->getContents($resource), $resource);

        return new \DateTime($commit['commit']['committer']['date']);
    }
{@inheritdoc}