Some of the templates included with the Calendar Printing Assistant begin the week on Sunday, some begin it on Monday. What do you do if the template you want to use begins on the wrong day and changing the first day of the week in File, Application Settings doesn't change the first day of the week in the calendar you want to print?
Easy... edit the template.
To make the change in 2-page templates, you need to make two simple edits in two files.
In Cal\Metadata folder, edit the Metadata.XML file to include <FirstDayOfWeek>sun</FirstDayOfWeek>, as seen in the screenshot below.
Next, open the Content.XML file (in the Cal folder). Search for mon..wed and replace it with sun..tue. Search for thu..sun and replace it with wed..sat. There should be two instances of each phrase, but it's much easier to use search and replace in your text editor.