Ever looked at a carton of milk's “use within X days of opening” trying to remember when you open the darn thing. Here is a solution which. I'd add, that they should have used that lottery ticket silvery scrape off stuff or something the like, so you don't need to get a pen and fear making a whole in the carton. Also it's not all pencils of pens that can write on printed carton.
![milk carton date open checklist](https://i0.wp.com/miklasnjor.com/wp-content/uploads/2017/12/210620132206.jpg?resize=840%2C472&ssl=1)