I need an IPN script for PayPal Subscriptions (PHP) that supports trial periods. It needs to validate incoming info and needs to calculate expiration date for each transaction.
I have started working on this and have some of it done(I can send files and mysql db) but can't figure out how to work trial periods. Unable to calculate expiration date because PayPal IPN doesn't distinguish between periods. I need to find a way to make this work.
I could be completely off in the way I look at this, so you are free to do whatever you think is best.