Wordpress Tracking

Find the best way to auto-track time usage any user that I have selected to track. I want to track time and date of each url click and or other activity, as well as see the elapsed time between those activities, and a receive calculation for that day of how much time that person is "likely" to have been working based on our metrics. So far I have this tool called Who's Online that gets me part way, but not all the way.