In reply to:

On 99% (if not more) of our calendars the first day of the week is printed up as Sunday.

This is certainly true on almost all of the wall calendars here in the USA that show a month at a time. Frequently business oriented one day per sheet calendars will lump Saturday and Sunday together on one sheet but they show no preference whatsoever for start, end or any specific time during the week unless they have day names in German (Wednesday is Mitwoch, mid-week). When I was in Russia several many years back in January I picked up a calendar in Russian. They have Monday as the first day of the week and I found the calendar almost impossible to use because of that. I still think of Monday as the beginning of the week. Is this a contradiction?