Well, it depends. If someone other than us has created the learning path, he or she calls the shots, meaning he or she decides how long the learning path is.
On the other hand, if we (Crammut) create it, we set the duration of the learning path based on the tasks it includes. For instance, we give you one day to read a blog post, two weeks to read a book, and so on. Remember that you can edit the duration of your learning path by clicking on ‘Options’ > ‘Change duration”.