Premium subscribers can approve multiple applicants from the same available shift. This allows you to create just one available shift and staff as many people as you need.
From your Dashboard, you'll see the shift application notification and the option to choose:
In the next window, you'll see all applicants listed in the order they applied. You can select multiple people and then also choose to close the available shift (which removes it from the schedule and doesn't allow any more employees to apply) or keep it open (allows employees to continue to apply for the shift).
Once you've approved multiple applicants, you'll see separate, but identical shifts appear on the calendar for each person.