I don't think I'm the only one on here that has wondered about what era the books are set in. But because the series takes place in mostly a fantasy setting, one without much modernization, it is relatively difficult to pin point an approximate year. Well, this was something that I've been curious about for a wile, and so, when I was lying in bed one night for some reason I remembered the Nightwing short story in the back of Stormbound. And realized that the answer to salving the mystery was most likely in there. So the next morning I opened up my copy and started reading. Sure enough, I found a clues that seemed to be putting me on the right track, so after a quick google search this is what I found:
Nightwing uses the term 'zoo' repeatedly when he recalls his time spent locked up by the landwalkers. The first zoo to be called a zoo was established in 1826.
That means, the absolute earliest the books can be set in would be 2226, considering that Nightwing hibernated 400 years shortly after his escape. So yes, that means TGH could be an omen for the future.