Okay, this is ridiculous.
It seems that CultureInfo.CurrentCulture in WinRT returns whatever's at the top of the language list, not the regional settings. This means that despite the fact that that very same list indicates that Dutch (the second entry in the list) is used for date, time and number formatting, in fact that's not true, at least not for WinRT apps (it is for WinRT). Of course, if I do put Dutch at the top, now the apps actually display in Dutch, which I don't want either because it doesn't match the UI of the rest of the OS (oh, and since IE now also integrates into the language list this also has the effect of turning half the web Dutch, which I again don't want).
This leaves us with the following:
- There are two places to set regional settings. One applies to the system and desktop applications, the other to Metro apps. The former is actually called "date, time and number formats", the latter is implicit from the language lists with no indication it has this effect.
- It is not possible to have metro apps use a different regional setting from their display language.
- It is not possible to customize the regional settings (since any customizations you make in the control panel only apply to the system and desktop apps, not metro apps).
Which idiot approved this design!?
Language settings have always been nothing but trouble. It's very simple: my Windows UI is in English, therefore I want the UI of everything else to be in English to match. However, I do like to use Dutch date and number formats. I have always hated applications that assume that because my regional settings are Dutch, I must prefer Dutch UI (despite the fact that the system UI language is English). And now, all Metro apps behave this way.
At least previously I could set my regional settings to English and then manually change them to match the Dutch settings. But that's not possible anymore either, because customizations are ignored by Metro apps in favour of the all-mighty language list!
How on earth did MS actually manage to make this worse!?
This is just infuriatingly stupid. It's very simple: UI languages (for web pages, apps or anything) should be determined from the UI language of the OS, nothing else. My regional settings or the location I'm in have nothing to do with what languages I speak. Why can't anyone get this right?
EDIT: One correction: if the language at the top of the list matches the one you've selected for the regional settings, any customizations you make do apply to Metro apps as well. I guess that's an acceptable workaround for now, but I still think this design is stupid. Metro apps should just use the regional settings, or if the language list is the way the separate option for regional settings should've been removed.