You can use Clarity for time tracking if you have your resources and projects with tasks in Clarity.
You can get the time entry data with queries from the database or with XOG in XML format.
There are also connectors for connecting Clarity to other systems which can be configured to meet the needs.
Like Clarity Connect 2.0 Integration Adaptors from Digital Celerity
http://www.digitalcelerity.com/Resources/Documents/Clarity%20Connect%20v2%200%20-%20Clarity%20Integration%20Adaptors%20from%20Digital%20Celerity%20LLC.pdf
and Integration bridge from ITroisolutions
http://itroisolutions.com/integration_bridge.html
There have not been answers to your post. The reason could be that you would need to have the same or related mappable data in both systems and it should be difficult to find economical justification to have two systems with the same cabability.
Martti K.