What is the era of Shadow and Bone?

The era of the novel Shadow and Bone is unspecified in the work and by the author, but some context can help us define it to an extent. This book is not necessarily set in any normal terrestrial time period, and by the very nature of it being a fantasy novel, it is set in an entirely alternate reality that does not constrain itself to our Earthly history. However, it does line up with roughly the late 1800s or early 1900s.
The characters do not ride in cars, and they dress and act in ways that are decidedly Victorian—so it can be assumed that the novel is supposed to take place roughly in that era. Carriages are used, as well as skiffs, and the military uses guns, so it is clearly not ancient times, but it is not advanced to the point of using modern motor vehicles it seems.