It is important to note that you are unable to add events into the schedule if you currently have "My Schedule" selected. You must select "All" or any of the specific schedules that you have created.
You can add a new event by moving the mouse to the date. Two icons will appear: on the left, you will see the icon '+', which permits to add a new event, on the right you will see another icon that permits to have an overview of the instructors or to delete all the events of that day.
You can add a new event also clicking on ''Options'' under the schedule, towards the bottom of the page, and then clicking on ''New event''.