Modify or create a date for the future in a workflow

I’d love to be able to set up a future date through a workflow. I think this could have many use cases, particularly in emails and also for triggering future workflows.

For example, imagine you are setting up a subscription service. A user signs up for this subscription through a form. Once that form is submitted, a workflow is triggered to shoot them a confirmation email. In the confirmation email, you may want to tell them when their subscription will renew. Right now, there’s no way to set that future date without doing it manually.

A feature like this would be very useful in providing important information to customers.