Within Teamwork Projects, you can create a calendar event and associate it with a specific project.
To create a new event, go to the Calendar area of your site.
When creating an event in the calendar, go to the privacy tab to select a specific project to associate the event with.
When an event is private to a specific project, only members of that project will see the event in the calendar view.
You can also allow any member of the chosen project to amend and edit the event as needed.
You can tell if the privacy on an event has been associated with all or specific projects if the person icon below is showing next to the meeting time.
For more information, see: Creating recurring events