I apologize in advance if this is the wrong forum for this question.

I'm trying to set up repeating events to stop repeating after a given
date.  In this case it's classes I'm taking this semester that need to
repeat once a week so I enter them like:

*** Programming Workshop
     <2012-01-24 Tue 13:30-14:50 +1w>, <2012-01-20 Fri 13:30-14:50 +1w>

The agenda shows the class being scheduled each tuesday and friday but I
would like to tell it to stop repeating at the end of the semester.

I didn't see anything helpful here:
http://orgmode.org/manual/Repeated-tasks.html#Repeated-tasks

The options I see here are using C-c C-x c to make a bunch of duplicate
entries (which seems a little messy to me, but perhaps this is just how
it's done) or simply marking the item as DONE at the end of the semester.
The latter option seems a little weird to me too since it would make my
agenda for the following semester cluttered if I was looking at it to plan
future events.  Is there an option I'm overlooking?

Thank you,

Peace
~Sam