Autovacuum ideas

I have an idea/request for the autovacuum daemon.

As far as I can tell, there is no way to tell the daemon to only do it's
work between certain hours. Could this be added as an option? In my
situation, I have tables that if vacuumed during the day would cause a
noticeable slowdown to my users and has therefore been deemed unacceptable
by management. This is one thing that is preventing me from turning on
autovacuun,. However, due to the activity on them, they really need to be
vacuumed daily. It would be nice to be able to tell autovacuum to run, but
have a way to tell it to always sleep during these hours (i.e. 7am to 5pm
daily). Has there been any thought into a feature like this?

Thanks,

Chris