Within Teamwork.com, you can associate calendar events with a specific project.
Click the More option in the main navigation menu on the left of your site and select Calendar from the pop-out menu.
Click the Add Event button in the top right of the Calendar area. Alternatively, you can update an existing event by clicking the event name in the calendar.
In the Add/Edit Event modal, go to the Privacy tab and select the Members of a project can see this option.
You will then be able to choose a specific project to associate with the event using the dropdown menu. You can also choose whether project members (excluding collaborators) can edit the event.
When an event is private to a specific project, only members of that project will see the event in the calendar view. A user icon will appear to the left of any meetings associated with projects.
For more information, see: Creating Recurring Events