private function determineSymfonyState()
{
$now = new \DateTime();
$eom = \DateTime::createFromFormat('m/Y', Kernel::END_OF_MAINTENANCE)->modify('last day of this month');
$eol = \DateTime::createFromFormat('m/Y', Kernel::END_OF_LIFE)->modify('last day of this month');
if ($now > $eol) {
$versionState = 'eol';
} elseif ($now > $eom) {
$versionState = 'eom';
} elseif ('' !== Kernel::EXTRA_VERSION) {
$versionState = 'dev';
} else {
$versionState = 'stable';
}
return $versionState;
}