Most definitely purchase tickets for the latest flights out and earliest ones returning. If you dd/ds is excused early and they can get to the airport early and catch an earlier flight home. They may have to pay $50 for it, depending on the airline, but having an extra 5 hours at home was worth it for our son. This is how we did this. We would find out from our son when his last exam was. Then we'd call the airline to see if they had extra room on earlier flights. We'd email him back to tell him the information the night before his last exam. Usually by then they'd know that they could leave after their last exam. He'd go to the airport early and get on the earlier flight if the seats hadn't been sold out. Yeh, he paid $50, but it was worth it to him. Also, this way he and his friends could visit at the airport outside of KP. It was a blast for them. And they were in uniform, which is mandatory. People are very generous in many ways. One of his buddies consistently got bumped up 1st class too. Sorry can't remember the airline. Eventually when they get their phones it's easy for them to prepay the change on the phone, instead of showing up at the airport on departure day and paying.