The tracking control module is adapted to track time usage (e.g., during a user's subscription to a particular service) on a disconnected client over a period of time with limited server interaction in a manner that is not likely to be affected by system clock changes. The module is designed to take an initial read when an executable associated with the service starts. As the program runs, the running time during the service life can be tracked by the module based on computer cycles that occur over the service life rather than on the system clock. In some embodiments, the system clock is only relied upon to track the time between service lives during which the program is asleep, thus minimizing the affect any system clock changes would have on the accuracy of the time estimate. The module adjusts the time left in the service period according to the time determinations.