Update a date field using another date field error message

Update a date field using another date field error message

We use contracts in our business and i am trying to work out how to update the start date of the ocntract vy using the end date of the contracft and substrcting the term in months from the end date.

I have got that part to work fine, however I am having diffciulty getting the field to update in the form using the following code:

Please can we have alook and see where i have gone wrong?


contract_details = zoho.crm.getRecordById("Product_Information",product_informationId);
info contract_details;
rental_start_date = rental_end_date.submonth(60);
info rental_start_date;
mp = Map();
mp.put("Rental_Start_Date",input.rental_start_date.toString("yyyy-MM-dd"));

update = zoho.crm.updateRecord("Product_Information", mp);
info mp;
info update;