src/model/UserDbLdap.php
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 $result[0]->getFirstAttribute('msds-userpasswordexpirytimecomputed');        
    }
public function getPasswordExpiryDate() {
        if ($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');        
    }
Get the password expirytime
See: https://msdn.microsoft.com/en-us/library/cc223410.aspx