When a user buys a subscription he's moved to a group "subscribers" with access to a bunch of files, to be removed automatically after 365 days.

Here's the rub. I cannot allow him to view files published *before* the date he joined the group. Only files published *during his tenure* in group "subscribers" are for his viewing. Past files are sold as a database as a separate product.

Is it possible to create a group "subscribers" able to view pages for 365 days, but only where page creation date > "joined group subscribers date"?