Scrum considers tracking the time individuals spend on individual tasks to be wasteful effort.  Scrum is only concerned about time when it comes to the time boxes of the Sprint and Sprint meetings.  Scrum also supports sustainable development, which implies working sustainable hours.  When it comes to the completion of tasks, the team is committed to delivering value.  The tasks in the Sprint Backlog represent the remaining tasks that the team has identified for delivering on its committed increment of potentially shippable value for the current Sprint.  The tasks themselves have no value and therefore should not be tracked.  Scrum is only concerned about burning down to value delivered.  Time spent on individual tasks is irrelevant.  What if I track my hours or my “actual” time on tasks?  This promotes a culture of “bums in seats” – that it is more important for people to be busy at any cost instead of getting valuable, high-quality results.  This also promotes bad habits such as forcing work into billable hours even though it is not.  Overall, time tracking in a Scrum environment does much harm and can undermine the entire framework.