GIVING FREE BRODUCT BASE ON DATE & NUMBER OF PRODUCT BOUGHT

Below is a script i need help modifying.

function calcTVI() {
var rowNumber = event.target.name.replace("TVI.", "");
var startDateString = "01-08-2022";
var endDateString = "01-09-2022";
var discountedProducts = ["ORANGE", "APPLE", "BANANA", "GRAPES", "MELON"];

var startDate = util.scand("dd-mm-yyyy", startDateString);
var endDate = util.scand("dd-mm-yyyy", endDateString);
var now = new Date();
event.value = "";

var qty = Number(this.getField("QTY."+rowNumber).valueAsString);
var product = this.getField("Products."+rowNumber).valueAsString;
if (discountedProducts.indexOf(product)!=-1) {
if (now.getTime()<startDate.getTime() || now.getTime()>endDate.getTime())
event.value = "N/A";
else if (qty>10)
event.value = Math.floor(qty/10) + " Free Ctns";
}
}

• each product should have its own promo start and end date.
• Number of free product for a set number bought to vary as well

e.g., orange promo date start 13-03-2023 & end 28-03-2023. for every 25 oranges, the customer gets 1 free. 

Same thing goes for the other fruits; different dates, different numbers to buy for a free product.

Thanks