How to select date_added field from products table?

Question

PHP

In general, products of a certain category are displayed on the page. Some data comes to the template, such as product_id, href (for the product), name, etc. You also need to select the date_added field from the oc_product table. Already rummaged through almost all the controllers, from var_dump'il wherever possible, and did not manage to find "the very place".
I would be very grateful to anyone who will facilitate my search!