My last project was Scheduler where my program was to take in a starting date of a school quarter, the date a break began, the date it ended, and the days of the week the class met. It was to then print out every class day.
This problem doesn't appear tough but it did give me some problems. I had to rewrite it once in order to take into account certain things I hadn't considered. What ended up giving me the most trouble was when a quarter began in one year and ended the next. I never fully solved this and my program adds one extra day. I ran out of time.