Within Teamwork, you can integrate your site with Harvest which allows you to use a Harvest timer directly on tasks in your projects.
Once connected, you can enable Harvest timers on individual projects.
You will first need to authorise Teamwork to connect to your Harvest account. To do this, click your profile icon in the top right of your site and select Settings from the dropdown menu.
In the settings area, go to the Integrations tab where will see a section for Harvest Time Tracking, where you can enable Harvest timers.
When you click Connect for the first time, you may be prompted to authenticate with Harvest.
Once this has been enabled for the site, you can choose whether to enable the Harvest Time Tracking integration on a project.
For more information, see: Enabling the Harvest Time Tracking Integration on a Project