Within Teamwork, 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 and click the Add Event button in the top right.
In the add 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.
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