Scenario:
If a client's name is changed in Web TimeSheet, all the timesheets which has that client's name associated with it, will automatically have the new name updated. This will include all Historical Timesheets having an association with that client.

Example:
A client ABC is associated with a project and users have been entering time for that project. For business reasons the client's name has to be changed to ABD. This change will affect all the existing timesheets, which has this client name on it and reflect as ABD.