Creating a subscription action set 7 days after a set date

Hi there,

I have a subscription that is auto charged after a user completes a 7 day trial. This is tricky because the user can set their trial start date to whenever they would like and the end date is 7 days from that start date they choose. So I have a custom field for “trial start date” and “trial end date.” I want the subscription to be auto charged a day after the “trial end date.” Right now, if customers purchase a trial and set their start date to a few days later, they are getting charge prematurely.

Is there a way to make an action set with a rule that says charge them only if the current date is after their trial start date? Or any other way to do it?

Hope this makes sense. Thanks in advance for anyone’s help!