R has a function Sys.timezone which tries hard to
retrieve the same information. However, we have found instances
where it failed to provide an answer---whereas the simple code in
this package does.
This package provides a single function gettz which looks
at /etc/timezone (on Debian/Ubuntu), /etc/sysconfig/clock
(on RedHat/CentOS/Fedora) or /etc/TIMEZONE (on Solaris).
In case no information can be provided, NULL is returned.
Windows support is bare-bones: the package builds, but does not do
anything. One could probably deploy custom code to query the registry
but given that R already does, there is imminent need.