1. Please login to your store account and open Purchase History page.
https://store.brainstormforce.com/purchase-history/
2. Click on the 「View License」 link of your purchase.
3. On manage license page you can check the exact expiration date of your license.
Note: The expiration date of your license would be exact 12 months from the date on which license has purchased / expired.
Example: If you purchased in July 2016, and renewed in May 2017. Then your license would expire in July 2017, giving you one full year ( 12 months ).