This will likely be the final release of this library. From here you should migrate to C++20 as vendors begin to ship this library under namespace std::chrono.
The master branch will continue to be bug fixed as bugs arise. However a subsequent release may or may not happen.
The CMake support of this library is chaotic (to be kind). Personally I don't use it and instead follow the installation instructions found here: https://howardhinnant.github.io/date/tz.html#Installation (needed only for tz.h).