The game can hang up on the transitions. It helps not to have any mail in the mailbox, and to have as little as possible in personal or family inventories.
But also, if you have a heavily customized home town, with lots of extra venues and custom lots, and a lot going on outside the school town, that can take a long time to load.
Since it can crash on transitions, what I try to do is pause and save my game on Saturday morning after final exams. That way I have saved all my academic progress if the game bugs or crashes during Graduation (pro tip - head to the gym annex early, and beat the crowds - if you are already there when the event call comes (11:00 AM, IRC), you won't have to wait long in line to graduate) or if the move home fails for whatever reason.
