Hello, I guess that you're trying to said license , if so, in the mail that Eset send to you, when you've adquiered NOD, appear the expiration date of your license. If you don't have this mail, you can contact Eset or the representant that sold you the license. Paul can reply better this question.
The new program comp. update 2.000.8/9 available shortly will support automatic notification so that you'll be informed when your license is about to expire.