This comes up constantly, so we relented and changed our renewal policy just so we’d stop getting the emails. The short version is that until very recently, a renewal was applied to the existing expiry date of your license, regardless of when you actually purchased the renewal.
This was the fairest possible way we could do things - I wanted to reward customers who renewed “on time” instead of rewarding the ones who wait. If you wait a month for a new release, but I renew right away, over time you would gain access to more new features than me, even though we paid the same money, and I didn’t think that was fair.
This was plainly written on the renewal page, and our “how the license works” page, neither of which anyone ever actually reads, so people would blindly renew 6 months after their license expired because a new update came out, then email to complain that for some unknown reason they only got 6 months instead of a year.
We have changed the policy so renewals in the future will apply from the day you renew, and if you renew when the key expires you get extra time, to reward those who support us.