You can check your Secure Certificate Expiration date anytime you want.  Note:  please allow 7 days lead time when asking us to renew a secure certificate for your domain.

The steps vary a little bit from browser to browser, however the are substantially the same.  The following example is using Google Chrome:

Open your web site.  Click on the lock in your browser address bar (our site is provided in this example)

Choose View Certificate from the drop down menu and click where the arrow is indicated:

You can see who the certificate is issued to (should be your web site) and the expiration date/status: