It's been a while, so I can't remember how long exactly, but I think it was about a week, on and off. Fortunately the different sections turned out well on the first or second try, so I didn't have to spend a lot of time redoing them.
And like the tutorial mentions, you really only have to do 1/6th of the knotwork. (or 1/3rd, 1/4th, 1/7th, etc.)