Scheduling

I have a web application that is storing a series of classes during a single month. I need to be able to take that schedule and move it ahead by one month but the classes are done by the day not the date. I have figured out how to get it to change the date to the next month but that puts them to the wrong day. I tried adding 4 days to move it forward to the proper day but that wont work because not all months are the same and I miss the first week. I then found where I can just use the AddMonths method but same problem. I am stumped on how to get it to move forward to the same day just the next month.