Adding new days

Good Morning- Am I supposed to be adding each new day's movements to the previous days? In other words, for day 3, should I be doing movements from days 1-3 and building on that each day, or am I only supposed to do the movements of the day?

I believe that the intent is to complete the current day, and then go back and work on previous days if you are able.

I'm one week in, and there were a couple specific movements that were difficult for me so I've been going back to the ones that need the most work each day and hitting them a couple times.