Project Schedule is a field that represents whether the project is on schedule or not
The Schedule field is currently not calculated in any way, but is included so you can manually set a schedule level on a project.
This setting allows you to edit or create new Schedule levels that can be set on a project.
The image below shows the default schedules: Before, On and Behind (Before schedule, On schedule and Behind schedule):
You can add new schedule levels or edit the ones in the table. Clicking on the palette icon shows a color picker dialog.
The red "X" deletes the row.