Hey chrisyip,
Both Knewton courses -- Complete Prep and Premium Live -- consist of 36 hours of instruction through video. While a month isn't long enough to follow a live class schedule (those run 6 to 8 weeks), we've definitely had students go through every course session by on-demand video in less than a month.
At the very minimum, we recommend studying about as much time outside of class as you spend in class -- so over a month that would be an additional 36 hours total. This will give you enough time to complete the homework assignments, practice questions, and assessments required to master the material (and to qualify for the Money-Back Guarantee). As I said, we do have many students that complete the course in less than a month. It all depends on how much time you're able to set aside for your studies.
Hope that helps, and let us know if you have any more questions!
Chris