To open the team calendar, click on the Team tasks button in your left side menu under the Teamwork section and choose Calendar on the top navigation menu.
By default, the calendar opens on the monthly view, with the due dates of tasks assigned to all team members and incomplete.
The color of the circle next to the task labels represents the first shared subject of the task. So if your task is shared on a subject that has a red color, the task in the calendar will reflect that by displaying the red color as well.
The team calendar allows you to filter tasks by member. You can select to display any member or guest tasks, all of the team tasks at once, as well as unassigned tasks.
If you are not familiar with the Azendoo calendar basics, learn more here.