I have an application that users can use it 14 days without paying. However, after 14 days users will not be able to use the application unless s/he pays for it.

I don't know how to track the remaining time for the free trial. I'm thinking of setting an cronjob 14 days later when the users is created but I think it is a bit hard to manage (?).

The second thought would be checking the remaining time for every user at a specific time every day but timezone and server loading might be problem in this case.

I'm using MongoDB and Node.js for back-end and HTML, CSS, JS for front-end. How can I design my database and code to overcome this problem?

Thanks in advance.

I believe this question have enough detail please warn before closing.