It isn't an American thing..... That's just it. It's ALL of the Americas, north and south. It's China, India and the Pacific Islands. You're quite outnumbered. Sunday is the first day of the week. The Islamic world has weekends on Friday and Saturday... The first day of the week is Sunday. In Saudi Arabia, it's Thursday and Friday. So, again, the ISO is incorrect. Their calendars start a week on Saturday. So just like the ISO is wrong for most of the worlds population writing dates as MMDD, it's wrong on the printed calendar. So... Crazy American that. We're following the "standard" and you aren't on one, and you're following the "standard" and we aren't on the other. Crazy Europeans.