It doesn't interact with that at all. It's a replacement for the parts of libtimezonemap that complete city names, but without the dependency on gtk (see bug #1436211) and without fetching anything from the network (we've had a lot of reliability issues with it and users apparently expect the panel to work offline, too).
I'm probably going to deprecate everything in libtimezonemap that isn't the map itself - or even move it into unity-control-center and ubiquity, so that we don't have to install libtimezonemap at all anymore.
> How does this interact with libtimezonemap
It doesn't interact with that at all. It's a replacement for the parts of libtimezonemap that complete city names, but without the dependency on gtk (see bug #1436211) and without fetching anything from the network (we've had a lot of reliability issues with it and users apparently expect the panel to work offline, too).
I'm probably going to deprecate everything in libtimezonemap that isn't the map itself - or even move it into unity-control- center and ubiquity, so that we don't have to install libtimezonemap at all anymore.