/usr/share/zoneinfo/posix/SystemV/AST4 is in tzdata 2016d-0ubuntu0.16.04.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/zoneinfo/posix/SystemV/../../SystemV/AST4
/usr/share/zoneinfo/posix/SystemV/../../SystemV/AST4