Roman numerals and red Sunday

What is the story behind these in the date window? Just a fun feature or used in specific countries or perhaps maritime? My 6309-7040 has Roman numerals and I find I often wear it on Sundays just to see the red square. It also has mon/tue/wed but I like this. Google didn't help much but perhaps here someone knows.

Some pics might help. Not near my own watch so pics from the interweb.

http://img.tapatalk.com/d/13/02/20/u3yhybyv.jpg
http://img.tapatalk.com/d/13/02/20/2ygurema.jpg

The I through VI an red square are for those places that do not use the western Monday, Tuesday, etc. week....

Thanks but the question remains which places these are. And why Sunday is red and not a Roman seven (VII).

On wiki I found this:
In the Baltics and Russia, the days of the week, are often written as Roman numbers, I being Monday.

But not really sure if seiko aimed for these regions thirty years ago.

Funniest answer I found for red Sunday so far is to warn you your workweek is about to start.....

Quote:

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Originally Posted by Glen Goyne

Thanks but the question remains which places these are. And why Sunday is red and not a Roman seven (VII).

On wiki I found this:
In the Baltics and Russia, the days of the week, are often written as Roman numbers, I being Monday.

But not really sure if seiko aimed for these regions thirty years ago.

Funniest answer I found for red Sunday so far is to warn you your workweek is about to start.....

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I think that Seiko has always taken the scatter gun approach to markets: aim at the market, sure, but make sure that you produce a enormously wide variety at a wide range of prices, so that for any watch wearing entity, there will be at least one model which will appeal.

Best wishes,
Bob

Took a pic on Sunday. Still don't get it but I like it!

http://img.tapatalk.com/d/13/04/01/vy4umabu.jpg