Around 40 hours plus photographic assignments.
Each section of the course will take around 1 to 2 hours to complete.
Overall you should take around 40 hours to complete the course.
You work at your own pace - you can work through all the tutorials over a period of weeks or months.
Each section has it's own assignment,usually a photographic task, while each task won't take long on it's own you should include the time taken to prepare, go and shoot and examine pictures.
If you allow 1 week for each assignment then the course will last 6 months.
You do not need to complete all assignments, but you will have to complete a final photographic test.