Then I randomly ask students how many 3 unit classes like mine they are taking. I tell them that the university expects that a 3 unit class is a 12 hour time commitment. That includes the time they spend in the classroom. So, if you are taking 3 classes that equals 36 hours. Then I ask them to deduct the number of hours they work at a job from that total.
Most students quickly run out of hours.
But, in the process of doing this we've all been talking, suggesting activities which take up time, and usually laughing in shared misery about how over-committed we all are. It also give me another opportunity to tell them that I understand that there will be weeks when they have to make choices about where they are spending their time and it might not be in the class they are taking with me. The exercise also allows me to reinterate that if and when they run into a time management problem, they should come right away to speak to me about it so that we can try to arrange a way for them to do the work required and still keep their other commmitments. And, of course, he or she is always right.