What is the best way to implement the function of decreasing days with an interval of 1 day (Cron/MySQL Events)?

Question

MySQL

Which implementation will be more competent, there are ads in the database, when adding them, they are assigned `days` = 30.
It is necessary to reduce the days by 1 daily, in what way is it better to implement this?

Answer 1

Maybe store the placement end date in the database right away?