After you have added tasks to your project, you can include tasks that have a due date on the timeline at the top of the Tasks page.
There are two ways to do this:
Add to Timeline button On the Tasks page, click in the space to the left of the check box for each task that you want to add to the timeline. This selects each task. On the Tasks tab, in the Actions group, click Add to Timeline.
Open Menu Click Open Menu (…) for the task that you are adding to the timeline, and then, on the box that appears, click Add to Timeline .
If a task has a start date and a due date, it appears on the timeline as a bar that spans those dates. If a task has only a due date or a start date, it appears as a single point on the timeline, marked with a diamond.
Tip: In traditional project management Gantt charts, which are similar to the timeline on the Tasks page, diamonds are used to indicate milestones in a project. A milestone is a reference point that marks a major event in a project, and it is used to monitor the project's progress. Some examples might be an important event, a completion date for a related project, or a release date. You might consider including start dates and due dates for most of the tasks in your project, and identifying milestones in your project by only providing those tasks with a due date (no start date).
As soon as you have added a task to the timeline, there are several things you can do to change the way the timeline appears. For more information, see Change the appearance of the timeline.