That is why Google Classroom as built in features to simplify your life and keep track of what's due and when.
What's Due?At the top left of any class on Google Classroom, you'll find a box that shows what's due and when. This will help students keep track of important assignments. Need to see everything? Just click View All and you'll be given a window that allows you to differentiate between what you still have left "To Do" and what you've already "Done".
Also, if students have more than one class in Google Classroom, they can keep track of assignments by using the Calendar. To access the calendar, just click the Menu Icon, and choose Calendar. From there, they can view a single class, or all classes to see what's due and when...