pg_restore usage

A while back, there was a thread on this list called "pg_restore
problem with 7.3.1". It outlined a scenario very similar to one I'm
having problems with. Granted, they're not serious problems (in the
sense that there's an acceptable workaround), but they suggest that
either pg_restore is not working as expected, or I have incorrect
expectations. I'd like to get some clarification as to which is the
case.

I dump a database as follows:

pg_dump -F c db >pg_dump`date +\%Y\%m\%d`.pgsql

I transfer this file to another server, where the database db does not
exist. I try the following:

pg_restore -C -d db pg_dump20040621.pgsql

I get this error:

pg_restore: [archiver (db)] connection to database "db" failed: FATAL:
database "db" does not exist

What is an example of how the -C flag is intended to be used? If it is
omitted, then the error is the same because no createdb has been
issued.

In the end, what I'm looking for is a nice way of taking a dump and
restoring it in one command that could be added to a crontab. I
realize that it's not too much extra work to create a shell script
that creates the relevant database, but this seems like such a natural
one-liner, and I'm curious what the intent of the -C flag is, if not
to precipitate such a situation.