System time zone is not properly detected with several symlinks

The system time zone is detected by following the /etc/localtime symlink. But if this symlink points itself to another symlink etc. before pointing to /usr/share/zoneinfo/ the time zone is not properly detected.

This can happen for instance when /etc is mounted read-only and the time zone of the system may change because the device is travelling (phone). Then, /etc/localtime is pointing on a mutable location in /run or /var that itself points to the right time zone.