It doesn't show on the calendar project view either. Thanks!
This functionality seems to be working only when using widgets.
To help you manage your project's progress, Jive provides visual cues that snapshot the project. On a project's home page (which you can customize with widgets, as with other main pages), you'll get a checkpoint timeline that shows where your checkpoints are between the project's start and finish, and where the current date falls on the timeline. A project calendar captures task due dates and checkpoint dates in a traditional calendar style.