Can we create due dates based on the day a student accepts the class in Canvas?  So a student starts a class on Wednesday.  I add him/her to the class, they accept the course, and from that date it calculates the due dates.  So for example maybe the due dates are 5 days, 10 days, 60 days from the date a student accepts the class?

We do not run classes like traditional institutions.  Students can start and stop courses anytime.  It's not lock step.