public function expirationDate()
{
$accountExpiry = $this->getAccountExpiry();
if ($accountExpiry == 0 || $accountExpiry == $this->getSchema()->neverExpiresDate()) {
return;
}
$unixTime = Utilities::convertWindowsTimeToUnixTime($accountExpiry);
return new DateTime(date($this->dateFormat, $unixTime));
}