With taming snakes it really takes as long as it takes. It's like people, each individual person has different personalities and becomes more tolerant of things at different rates.
That being said, the amount of time it takes for them to calm down is a direct reflection of how much time and patience you put into the animal.
My jungle python was absolutely psychotic when we got her and after 4 weeks (and hundreds of tags) she settled down. Short 10 minute handling sessions that are calm, respectful and peaceful do wonders. Don't over handle and stress the animal out, don't pull the animal off it's perch to try and handle it. Pick the animal up without hesitating or being fearful. Just lift them out, handle them and don't worry about the bites. It all comes together eventually.