The problem (report here) resides in zic, used by the KDE Date and Time module (and other programs), which copies the timezone to /etc/localtime without checking if the original is a symbolic link and therefore, without properly referencing it, so it ends up creating a broken league:
ls -l /etc/localtime
lrwxrwxrwx 2 root root 25 mar 14 10:46 /etc/localtime -> ../posix/Europe/Guča
To fix it temporarily:
sudo dpkg-reconfigure tzdata
Or a longer lasting palliative (and extreme):
sudo mv /usr/sbin/zic /usr/sbin/zic-bad
WellKDE can work without zic (other programs, who knows ;).