[tz] Another Newbie question

[Zefram]

Donald MacQueen wrote:
>'right/America/Detroit', 'posix/America/Detroit', 'US/Eastern', and
>'America/Detroit'.

The right/ and posix/ directories don't actually contain distinct zones.
They're the same zones compiled different ways, to handle systems with
different semantics for time_t.  They're generated by separate invocations
of zic; see the Makefile.  Any single system needs only one of the two
forms, almost always posix/.

Where both are installed, it is unfortunate that the two directories are
nested inside the main zoneinfo directory rather than being outside it.
The present way misleads people by making bogus names resolvable as
if they were zone names.  Logically, the main directory used for zone
lookup should be a link to one form or the other.  As it is, you'll
find that the individual tzfile America/Detroit is the same as the
posix/America/Detroit file.

-zefram