Really impressive, and de-motivating for me! :) I was working on something similar as a side project. The only information that was not easy to get, because it

Really impressive, and de-motivating for me! :) I was working on something similar as a side project. The only information that was not easy to get, because it was not delivered with every DNS request, is the "expiration date". How did you manage to get it? Or even more interestingly: Are you willing to give some insights, how you realised it?