trigger an event for evey month after signup.

Hi there,

I wants to do task, that is I have custom form on a page. I’m storing their values in database table.
I need to send email or other task(execute some code) for every month.
for example, for user1 signup on 18may, some code(or email) has to excute after 18june and so on(after30days). If user2 signup on 28may, some code(or email)has to execute on 28june and so on(after30days). Like wise for every user i need to send email on monthly basis depending on the days of their signup (like woocommerce subscription).

I know about cron job, but it only run on time basis. I needs to run the cron on user basis depend on their signup date for every month.

Anyone can help me, please?