Hello all, new here but been developing with PHP for a long time !

I've got a couple of sites that I intend to run as subscription sites. I'm currently writing the subscription handling backend and, as part of that, on my admin panel I want to show how many subscriptions are due to renewal on the current day and/or in the current week.

To do that I need to know when a users subscription will renew. It seems quite simple until you consider the situation where a user signs up on, say, January 31st. If their subscription renewal period is one month then it would renew on February 31st. Except that date is invalid. I'm assuming that Paypal will renew on February 28th in that case and then back to the March 31st.

Or does it ?

Thanks in advance

Phil