In order to add or adjust base floor plans you'll need to click the 'Scheduling' button in the top navigation bar, then click the 'Base Floorplans' tab.
Either create a new base floor plan or click the name of the base floor plan you'd like to edit. Then you'll be presented with a list of departments and shifts residing on them as shown below:
To edit the time of a shift, click and drag the ends of the bars.
You can add new shifts and navigate the floor plan section using the toolbar at the top.
You can also click the center of a shift's bar to edit the shifts properties.