Well, you could use a list application, but it would be very easy to lose an item (or due date) in that format and tarnish your grades for no good reason. You could use a general calendar, but if you have a busy schedule, your planner will get muddled quickly. Not to mention the annoying habit of many calendar programs to want to assign a specific time to each item, and your math problems don’t really need their own hour on the day they are due. A homework specific planner will give you what you need, assignments and due dates without the clutter.