public function setExtendedBounds(string $min = '', string $max = ''): self
    {
        $bounds = [];
        $bounds['min'] = $min;
        $bounds['max'] = $max;
        // switch if min is higher then max
        if (\strtotime($min) > \strtotime($max)) {
            $bounds['min'] = $max;
            $bounds['max'] = $min;
        }

        return $this->setParam('extended_bounds', $bounds);
    }