Classroom Scheduling Software

My school is in need of scheduling software, and I don't think excel is going to cut it. Any suggestions are greatly appreciated. Specifically, in the fall, we have a week when we suspend regular classes, and we offer arts-related classes for three consecutive days. The classes can last 3, 6, or 9 hours, and there are approximately 20 classes per day. Our challenge is scheduling 120 students for all of those classes without tearing our hair out. It's been done manually, but I figured that there is a better a way. Thanks!