You are right, originally they did. The answer is catholicism happened:
A religious purist, Jón made it his mission to uproot all remnants of paganism. This included changing the names of the days of the week. Thus Óðinsdagr, "day of Odin", became miðvikudagr, "mid-week day" and the days of Týr and Thor became the prosaic "third day" and "fifth day".
Even the german version is still close to this origin, Donnerstag is literally just Thunder's Day.
Another fun fact, while the norse pantheon is generally considered to be, well, nordic, before Christianity came they were also revered further down south by the Germanic peoples, sometimes under different names though (Odin = Wotan for example).
Huh, I thought Chinese was odd for using <#>day and <#>month instead of naming each one. Guess it's just english and Italian/spanish/french that's weird.
I mean the last 4 English month names are basically <#>month, but never got updated when the Romans switched from a 10 month calendar to a twelve month calendar. The suffix -ber comes from the latin word for month, with the prefix being the Latin number Septem = 7, Octo = 8, Novem = 9, Decem = 10. The two new months (January and February) were inserted at the start of the year throwing the naming off by 2.
July and August were originally called Quintilis and Sextilis so the 5th and 6th months and renamed after the calendar change, to honour Julius and Augustus.
Exactly the same applies to Portuguese: Janeiro, Fevereiro, Março, Abril, Maio, Junho, Julho, Agosto, Setembro, Outubro, Novembro, Dezembro. Only the names for days of week are different here: Domingo (Sunday), segunda-feira, terça-feira, quarta-feira, quinta-feira, sexta-feira and sábado. Colloquially (at least here in Brazil) we omit the "feira" suffix, saying just "quarta" or "segunda".
Actually some of the former British colonies and most of the Americas start the week on Sunday, Muslim World start on Saturday, Maldives on Friday, rest of the planet follows the standard.
That map is just what the Unicode consortium ( a California non-profit) decided should be used on it's standards.
It has zero authority on what day is the fist day of the week outside that and it certainly has not done any real research on what people actually use in all these countries.
Same with ISO 8601 in regards to dates. It's not actually used outside of naming sortable computer files (if even that) and certainly now used in common speech or official documents etc.
Simply put misrepresenting these maps and ISOs by generalizing what they apply to is wrong
Well, that's the ISO standard, so if you think otherwise, you are wrong :)
Well sorry I don't think SO.
Muslim World start on Saturday
Wait do we? Our firstday is Sunday, but Saturday and Friday aren't numbered (Sabbath and groupingday, respectively) so I couldn't tell you if they're the start or the end of the week.
Since it takes "their language" so literally as to have English majority nations with a different word listed, I wonder how many other countries on this don't actually use their version of thursday.
This map is not about a nation's word for Thursday but about the word in different languages. Austria for example isn't labelled with any word because Austrians speak German and the German word for Thursday is already placed in Germany. The English word Thursday is placed in England, its most logical location. The Gaelic word for Thursday meanwhile is placed in Scotland, its most logical place. This doesn't imply that the majority of Scottish people speak Gaelic, only that Scotland is the country with the highest number of Gaelic speakers while England has the highest number of English speakers in Europe.
Yes I understood that, but I'm saying it would be interesting to know which other places is a similar situation of not a regularly spoken language. Since I don't speak any Scandinavian language and know very few latin languages, I have no context of which of these are historic etymologic notations versus a word people actually use, but I bet there are a lot of them.
Political maps are a terrible tool for visualizing cultural / linguistic practices (and on this one, colonization didn't make it even worse). Just gotta roll with it and enjoy the weird assumptions :)