The Calendar icon shows up in the My Projects context box next to each project that carries its own iteration/sprint schedule. Projects that do not display the calendar icon, therefore, share the schedule of a project from above. The schedule may be defined for the direct project parent, if it carries a schedule, or from another project. The schedule will be inherited from the first direct ancestor project that carries a schedule.

When schedules are shared, velocity can be rolled up and displayed across projects.