There is a lot of discussion about time tracking when practicing. It depends on the type of person you are how much it will help you. 
In my case starting to structure, focus and then track has changed everything. I am making much faster progress than before simply by planning WHAT to practice and then making myself aware of HOW MUCH I have practiced it. Give it a try for a couple of month (register here)!

Below you will find some references regarding the subject.