I have a tool where a user can generate a HTML link to my site for use on their site. The link is to a redirect page that redirects internally based on a calculation on the URL parameters. For example, link is
example.com/2015-11-09 and the redirect calculates the difference between today's date and the URL parameter date. It then redirects to that URL, i.e.
example.com/diff/1, tomorrow it would be
Since the landing URL changes but original inbound link doesn't, would this type of link have a negative impact on overall site SEO?