Within Teamwork Desk, you can enable the time tracking feature to allow agents to log time on tickets.
It also gives agents the ability to log billable time for the ticket to a project on your Teamwork.com site.
To enable the feature, click your profile icon to the top right of the navigation bar and select Settings.
In the settings area, go to the Apps tab.
You will then see an option to enable the time tracking tool.
Once time tracking has been enabled, you will be able to adjust the settings under the General tab of your site settings. Select Time Tracking from the left hand menu.
You can enable the same set of time tracking settings for all inboxes on your Desk site, or customize each inbox individually.
Note: The selected settings will be enabled for all inboxes by default with the option to enable separate timer settings for each inbox by clicking on the checkbox for Customize tracking settings for each inbox.
For more information, see: Integrating with Teamwork.com