Course-scheduling systems seem to be a perennial request on Skunkworks-KE. Here's one built to run on AppEngine.
http://code.google.com/p/cloudcourse/
It's open source so you can run it on your own AppEngine instance. I haven't tried it but you may be able to run it on alternative AppEngine-like implementations (AppScale
http://code.google.com/p/appscale/
)
saidi