Random832 wrote:
And are built from the glibc source (or their own respective repository, in the case of other OSes) rather than the tzcode source.
Yes, and that's something that can be tricky when one talks about tz "version". For zic, zdump and tzselect the latest glibc is a copy of 2015g tzcode, and many distributions combine this with 2016f or 2016g tzdata. This is true for the machine I'm typing this on, which is running Ubuntu 16.04.1 LTS; on it, tzselect --version reports "zdump (Ubuntu GLIBC 2.23-0ubuntu3) 2.23", so it says it is a modified version of glibc 2.23; as it happens this part of glibc has not been modified other than by configuring the version number, bug-report address, etc. in the usual way. There's often not a single "version number" for the installed binary data files. On my machine the data source files came from 2016f and were compiled with zic that came from 2015g, and both version numbers are relevant to the installed binary data.