End of maintenance
For Huygens Nodelocked and Floating licenses the end of your maintenance contract with Scientific Volume Imaging can be seen in the License String of your Huygens Software, after the label "eom".
Start Huygens and go to Help > License overview. Your License Strings will be listed; they will look like this one:
HuEss-16.10-w-d6-tg2p9-mp-eom2017Aug01-04681546bc1cc372-{usermail@domain.com}-7eb8b829a2b03bb6acd0
The string eom2017Aug01 is the end of maintenance date of the license.
Extending the Maintenance and Upgrade contract
A maintenance and upgrade contract can be extended at any time. More details on what this contract includes can be found here.