When does an on-prem Gravity zone licence actually start counting the days ?

Due to some management oversight, we've had multiple locations buy their own licences that we plan to add into a single, centrally managed console. These locations got their product keys this week.

We're running an on-prem solution with no internet connection across the whole network if this matters.

Question is…. are we wasting licensing days if we delay adding the keys into the console? Did the countdown start when they recived the keys or does it start when we add it ?