Weekend Rate

Hi

I would like to have two rates per Km:
One for deliveries Mon-Fri
Two for deliveries Sat-Sun

I looked at the files and found this below. Is this the right way to go? Can you assist? Thank you

* This example shows how you can modify the $result var via custom function:
*
* add_filter( ‘wcsdm_calculate_shipping_cost’, ‘my_get_rate’, 10, 4 );
*
* function my_calculate_shipping_cost( $rate, $api_response, $package, $obj ) {
* // Return the cost data array
* return array(
* ‘cost’ => 0,
* ‘label’ => ‘Free Shipping’,
* ‘meta_data’ => array(),
* );
* }