code: public function getPasswordExpiryDate() {
          if ($this->username == null) {
              throw new \yii\base\Exception('Please set username attribute before calling getPasswordExpiryDate() function.');
          }
          
          $result = static::getAdldapProvider()->
                    search()->
                    select(['msDS-UserPasswordExpiryTimeComputed'])->
                    where('samaccountname', '=', $this->username)->
                    get();
          return $result[0]->getFirstAttribute('msds-userpasswordexpirytimecomputed');        
      }
docs: Get the password expirytime
  See: https://msdn.microsoft.com/en-us/library/cc223410.aspx