Hello!
That's a great question, and I can understand the confusion. Let me clarify a bit. Courses 1, 2, and 3 do run sequentially, one right after the other. These courses are each 8 weeks long. You're in the 4-course CDA program, so you are also taking Course 4, which runs concurrently alongside courses 1, 2, and 3. So, you have 24 weeks to finish Course 4.
I would need to access your account to see what cohort you are in so that I can give you definitive start dates for your courses.
I am also attaching an image below for more clarity. Let me know if there is anything else I can help with!
Best,
Rachel