These settings control which fields are displayed in the Appointment Diary Calendar.
Go to the Menu option, Setup > Field Selection > Calendar.
To select a field simply single click on it on the left.
To change the text displayed for the field just over type in the Name column.
Select whether each field is shown in the Weekly and/or Monthly Calendar.
To remove a field click the button
To change the order of the fields drag and drop them in the list on the right.
Distance
The special field Distance is only applicable in the UK or US. It will show the distance in miles from the currently selected Account to each appointment shown in the Calendar. Note that this requires the Google API details to be set up for the User. You can read how to set this up here.