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In Modern day English, the days of the week begin with
SMTWTFS. In order to use single letters for abbreviations and not conflict, the best I've seen is UMTWRFS.

The modern day Romance languages have days starting with M for both Tuesday and Wednesday, the Germanic tongues all have Saturday and Sunday both start with S. Even old English which used a Thorn for the first letter of Thursday, still had the Sæternesdæg/Sunnandæg issue. As far as I can tell from looking at http://www.omniglot.com/language/time/days.htm , the closest place to England with unique Day of the Week Initials is the Faroe Islands.

So with a POD of 500AD, how can we end up with the language spoken in OTL London have unique day of the week initials?
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