The combination of the time commitment and your ability to concentrate leads to the conclusion that you cannot cram your study time into a week-end of concentrated study. You must break up your study time into 3 to 4 hour study periods doing only one study period per day. You must establish a regular routine for each week. Students taking a regular semester course on-campus will count their class (lecture and lab) time and plan 2 to 3 additional study periods.
If taking a course via distance education, students need to plan for all of the course time, thus during a regular semester term, our 4 credit hour course example would require 3 to 4 study periods with 3 to 4 hours for each study period per week. If taking the course at faster pace (9 week summer term) you will need to schedule more study times. This may mean a 3 to 4 hour study period daily for 6 days a week (with only one day of as a day of rest).
You need to stay on top of a course to successfully complete it. Pacing yourself with multiple study times allows for effective learning. Students who procrastinate until close to an exam and then try cramming through course materials are rarely "A" students.