src/widgets/BaseActionsInfoWidget.php
protected function getValue($value, $type)
    {
        switch ($type) {
            case self::ATTRIBUTE_TYPE_USER:
                return $this->getUsername($value);
            case self::ATTRIBUTE_TYPE_DATE:
                return date('Y-m-d h:i:s', $value);
            default:
                return $value;
        }
    }
protected function getValue($value, $type)
    {
        switch ($type) {
            case self::ATTRIBUTE_TYPE_USER:
                return $this->getUsername($value);
            case self::ATTRIBUTE_TYPE_DATE:
                return date('Y-m-d h:i:s', $value);
            default:
                return $value;
        }
    }
Get pretty value by type
@param mixed $value
@param string $type
@return mixed