I searched "schedul" on hayoo!, but had no clue. It seems that I can use scheduleEventAt from Control.Monad.Event.Classes. But what is type "e"? It seems like an event. How do I define an event?

I have not learned Monad yet. Can some one give me a simple example? Suppose I want to run an external program "pg" which in Haskell's language has the type of String -> IO ().

Thanks,

Hong