holidays_charge.js

  var remove_payment = function(data) {
    var order_product_id = payment_cost_order_product_id(data);
    Jumpseller.updateCart(order_product_id, 0); // no payment cost on the order.
}

function payment_cost_order_product_id(cart_json) {
    var id = null;
    $.each(cart_json.products, function(i, order_product) {
        if (order_product.product_id == productId) { // product for adding payment cost. You need to create a virtual product with the additional price. The ID is the number in the URL of the product in the admin panel.
            id = order_product.id;
        }
    });
    return id; // return order_product.id if found
}

var productId = "3577772"
var domingoId = "6127680"
var feriadoId = "6127681"

function getWeekDay(date) {
    //Create an array containing each day, starting with Sunday.
    var weekdays = new Array(
        "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"
    );
    //Use the getDay() method to get the day.
    var day = date.getDay();
    //Return the element that corresponds to that index.
    return weekdays[day];
}

document.getElementById("order_other_fecha_de_entrega_de_regalo").addEventListener("change", function() {
    var input = this.value;
    var dateEntered = new Date(input);
    var dayName = getWeekDay(dateEntered);
    console.log(getWeekDay(dateEntered));
    if (dayName == "Sunday") {
        console.log("Agregar");

        Jumpseller.getCart({
            callback: remove_payment
        });
        Jumpseller.addProductToCart(productId, 1, {
            "Variant": domingoId
        })
    } else {
        console.log("Remover");
        Jumpseller.getCart({
            callback: remove_payment
        })

    }
});

function payment_cost_order_product_id(cart_json) {
    var id = null;
    $.each(cart_json.products, function(i, order_product) {
        if (order_product.product_id == productId) { // product for adding payment cost. You need to create a virtual product with the additional price. The ID is the number in the URL of the product in the admin panel.
            id = order_product.id;
        }
    });
    return id; // return order_product.id if found
}