Milestones are collections of Epics, which in turn are collections of Stories. You can access the Milestones Page by selecting "Milestones" in the Shortcut sidebar menu. Once there, you can start a new Milestone by clicking on the "Create Milestone" button in the upper left.
Visiting an individual Milestone’s page provides quick stats about the state of the Milestone and how it is progressing. It offers a table of all Epics in the Milestone as well as the Milestone's start and end dates, Labels, number of Stories and Points. From the Milestone page you can also edit the Milestone title and description and delete the Milestone itself.
Adding Milestones CategoriesTo create a new Category, first click on the click on the Add Categories button and click the Manage Categories option in the dropdown.
Then click the Add Category button, then name your new Category and click Create Category.
Editing or Deleting Milestone Categories
Then click on the pencil icon next to the Category name. To delete a Milestone Category, click on the trash can icon (note that you can only delete a Category if all Milestones have been removed from it).
Milestones can be deleted by visiting the individual Milestone page, clicking the ellipsis icon in the top right-hand corner, and selecting Delete Milestone. Any Epics within that Milestone will be replaced to the Epics Backlog.